To be honest, 20 was a really odd time for me - you're still in school which means you're kind of in limbo between teenager and adult imo. It's a VERY odd place to be.
So far I think I've enjoyed 25-28 (now) the best: I'm out of school with "adult responsibilities, I'm way more confident in who I AM now, things have really fallen into place recently, and I'm def looking forward to the future, but not in a "get me out of this NOW" way.
I do run into the "no kids yet?!" phenomenon here and there, but again, that's old hat for me since it's been happening since the mass birthing of my friends around age 25.
NBD now!