Why would you when you know that you can’t ‘trust’ yourself? The ‘self’ is not trustworthy. That’s not cynicism.
“The road to hell is paved with good intentions”.
Rumi wrote this about trust:
Be thankful not for the friend’s kindness
but for his tyranny.
So the arrogant beauty in you
can become a lover that weeps.
The nature and nurture model has been amply demonstrated - if you have acces to some twins and a few years to spare, you can try some experiments yourself.
What we don’t know about Trust has yet to be demonstrated. Our ideas about Trust (actual and potential ideas/models) are of course not (and can never be) a complete reflection of reality, they are concepts.
I’d say this poem is about the mirror of relationship. We see our chains in the difficult moments.
PS - I trust my cat to steal my food off the plate when I’m not looking - the dog has yet to jump on to the dinner table (Allah be praised!)
Dan: When knocked off our ‘perch’ (pedestal) there is a great flapping and flailing as we try to ‘get back’ to where the ‘comfort’ is, to get back to where ‘home’ is.
Trust is tricky.
The word itself derives from PIE root deru - ‘be firm, solid, steadfast’ - which is also the same root for the words true, truth, and tree. Trees are clearly very trustworthy! - and truth the most trustworthy of all.
A couple of dictionary definitions (as they apply here):
if you trust someone, you believe that they are honest and sincere and will not deliberately do anything to harm you (Collins);
or, more generally:
a firm belief in the character, strength, or truth of someone (Merriam-Webster).
As macdougdoug says above, this kind of trust is most likely to be established between people who already know each other very well, such as close friends, intimate partners, and families. It is difficult to honestly extend this level of trust to complete strangers (as many of us are on this forum).
One straightforward but problematic way of establishing trust on this forum might be to create an in-group of participants who each believe themselves to be the special repository of K’s insight/mutation (don’t throw rocks at me for saying so!), and who encourage each other to indulge in this because it maintains each member in their self-belief.
So trust can be established among an in-group at the expense of the out-group. We see this kind of problematic cultivation of ‘trust’ occurring in closed Facebook groups, or even cults, which often leads to the uncritical acceptance of non-rational and conspiratorial views.
A reaction to this might be to create an alternative in-group of people who are cynical about K’s insights/mutation, but it is clear that this would be merely a reaction.
A third way of establishing trust might be to admit some kind of common ground that we all share - such as human consciousness (and its contents). K has indeed suggested this as a starting point that we can all stand on together. But this common ground will be rejected by those people who believe themselves to be the special repository of K’s insight/mutation, or who give extra importance to those sayings of K’s which speak of rejecting society, being an outsider to society.
Maybe those of us who feel we share a common human consciousness (with its contents) can make a start - climbing down from our pedestals and treating each other as equals - but if others feel that they stand apart from human consciousness and are only speaking from pure insight/ego-lessness etc, this approach will be unsustainable.
So we are at an impasse - it seems to me - so far as trust goes. What do you think might be the way through?
I think that K is saying the same thing here : https://forum.kinfonet.org/t/an-exercise-for-looking-at-each-of-our-lacking-contentments/1525
Straightforward my A**!! 
The main problem being that we crazy kooks have difficulty recognising other crazy kooks as our equals.
No obvious Special K in group here so far to my knowledge.
I do actually believe that you/we are human, and doing y/our best. And I do accept and understand that our best is often pretty poor.
What do you mean by ‘not trustworthy?’ What can’t the self be trusted to do?
Still sounds kind of clinical. Is it merely a matter of psychology/evolution for you? For me it’s more!
Love. (though it does desire and cherish - which could be argued is the opposite of love)
Please state your case - unless you are just sharing your feelings.
Trust - as with all the other feelings we have, are productions of this body/mind (aka part of our psychology). What else would you like to add to the concept?
And important for a forum like this, I think.
But we are not complete strangers. We’ve all engaged with each other, often quite a bit for quite a while, here and in some cases in Zoom dialogues. We tend not to share personal information, but you can learn a lot about a person from what they say and how they say it.
Yes. Krishnamurti said trust comes with love, and nobody says love comes with a felt sense of shared being. That’s my pedestal and I ain’t comin’ down! 
My feelings are ‘my case!’ To me trust is deep, important, and mysterious. I’m guessing that doesn’t resonate so strongly with you. Which provides us both with a delightful opportunity to get to know a smidgen more about each other by reading between the lines.
We can’t transact trade without trust. Even before we became civilized, we traded with other groups of hunter gatherers. It’s that simple. It’s just practical to be trustworthy.
I hear you. But the K world (I’m not criticising K here) attracts a lot of prickly pears who often don’t feel any sense of shared being! - in fact, they are proud of it! - and this shows itself on the forum. It would take a lot of time and personal correspondence with some of these types to get to a point where they would just stop judging and being hostile, etc.
I also don’t understand why some participants get so outraged when they are asked direct questions (e.g. are you saying that you have wiped out the ‘I’? - or, are you sure about that? - or, don’t you see that this thing you have just said contradicts this other thing that you just said? etc), seeing as this is a discussion forum and not Speaker’s Corner. Some people - it seems - take engagement for aggression, and direct questioning for personal attack.
Love is such a needed thing in this world, and on this forum - but ideology kills everything, and sentimentally is a trap. We need to find a middle way… maybe starting with not being a judgemental so and so oneself!
What he said. 
So then we work with this, life is messy?
You asked me some direct-ish questions that I did not answer directly (if at all). Some time we should go into why that happened.
Another one of my favorite pointers to love: radical openness.
Ok. ‘You’ tell me that you have had a perfect insight and that you have no self, and that I should just listen to what you have to say without judgement or question. You are backed up in this by a coterie of faithful followers who apparently buy what you believe, and who then attack or ignore anyone for having the impertinence to be skeptical.
What is radical openness then?
You see, to me, to claim to have had a total insight (of the kind K talked about) when I have not had such an insight, is a sin, something harmful and damaging. It is morally, ethically, as well as intellectually wrong.
But to you (the hypothetical ‘you’ and your hypothetical followers) it is a right, a conviction, something sacred that must be defended against. Either this is because the insight truly is a total insight (and so one is quite correct to stand one’s ground); or, because one has so identified with what one takes to be a total insight, it is impossible for you to drop your stance and meet me as you are.
No doubt we all play this game from time to time - but when it becomes habitual and sustained, how can there be trust? Because then you (and your hypothetical followers) don’t trust me, and I don’t trust you.
So what does radical openness mean in this regard? Do I just let you make your claims and walk by as though I hadn’t noticed? And when I do notice and call you out about it, you call me names and raise hell. What is radical openness between people who are at such extremes of polarisation on these matters?
Radical acceptance of being on the losing team
If you start with trust and certainty soon you will end up with doubt and uncertainty.