I struggled with this as well, having not enjoyed my teenage years that much.

How I coped was to tell myself that people asserting that period X is the best years of your life are people whose lives peaked at that time, and that this won’t be true if I made sure to not have my life peak then.

I’m happy to say that I’ve proven the assertion wrong in my case. It’s been a steady climb upwards, with every year being better than the latter.