Whoops this topic is old, but I've been off for a while so I'll reply regardless:
I'm a bit ambiguous on the matter, yeah, I feel like I lack some sort of, dunno, natural maturity or something, but then I don't think it's all that desireable to be a... proper adult. So even if I gather all sorts of skills, mindsets and general tools to be a functioning adult lifeform, I'll be more than happy to keep loads of "childish" traits because actually, life's not all the serious.
Actually at the moment, looking a good 10-12 years younger than my age is a huge advantage, because I can get away with a lot more foolish bull->-bleeped-<- than I'm supposed to in my place in life

And i take FULL advantage of that, kinda catch up on my pathetic teen years...
From my experiences this is a feeling that many of my peers share, if maybe for different reasons, but I'm happy that for once it's something that doesn't only descends from my, ahem, little problem.