Keep in mind that Krishnamurti also said “the thinker is the thought”, which is one way of saying that thought is just a mechanical process that operates according to practical necessity.
For Krishnamurti, “mentally” and “psychologically” are not synonymous. If you recall, he said there are two kinds of thought: practical and psychological, and both are mental because thought is mentality.
But psychological thought is pathological thought because it is rooted in and supports the delusion that that I am the central character in a narrative that thought’s reactions are improvising from moment to moment.
I am the ongoing wishful/dreadful thinking of a fictional character in a fictional reality until I am forced to realize I don’t know who/what I am (if anything) because I can’t stop thinking.