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
Move to a new city, get a radically different job, get a kid, switch up your routine, pick up unusual hobbies/interests and every year will feel like a new life. Childhood feels very long because you have to go through mandatory checkpoints imposed from the outside, add that to your adult life and it'll feel the same. Why don't you go get a parachute intro course next weekend? Or rent a car on a race track? Go ice climbing next winter? Join a yoga club, a music class, a reading group, a dance class, &c. try things you don't necessarily want to do and you'll open many doors.
Most humans have a tendency to go the path of least resistance, and in today's world of working from home and unlimited screen based entertainment you can very easily waste decades your life
Much downside to this but the upside is my life feels incredibly long and I haven't even reached 50 yet. I have already lived numerous lives compared to the self that would have had a very stable life the last 25 years. My working life feels vastly longer than my very stable childhood. That came and went in the blink of an eye from this perspective.