IMO
Truth is related to our ego. What I believed as true (and important) as a young man, no longer applies and this process continues. If all my "truth" was taken away at once, I would be in danger of losing my ego state and my version of reality. This came close a decade ago, so I went back to physical reality as true e.g. I step off that cliff I die. I don't eat or drink I die and worked from there. Most truth is relative to the situation and our personal needs.