I think time perception is contingent on cultural and lifestyle factors, I don't recognise it in my own life. My twenties (chaotic) lasted forever, now in my 30s, this last year in particular felt incredibly long (it was eventful and full of change).
I rarely find myself on "autopilot". Is that why?
right things that are eventful and full of change take a long time, childhood is generally eventful and full of change. If having an eventful and changing life increases the amount of subjective life we experience how should we live.
Autopilot is a choice- most people are on it, some aren't. Society has always been like this. Society is attacking self aware and fully conscious people more than ever now though :(
I think you are on to something.
My theory is that the brain is good at compressing memories, so if you do mostly the same things every day it's not stored as a separate memory.
I actually felt my 30s as one of the longest periods in my life, because of things that happened in my life