Speak for yourself haha. This is a matter of trajectory. As you get older, you'll follow the trajectory you maintain. I exercise creativity more than fitness and I feel incredible hahahaha.

Here's the key: Balance practice with theory.

It's very sad to see so many people correlate creativity with childishness. What a farce!

Kids are an amazing source of inspiration, and I make a point to cherish every moment around them. But, as you grow, you will probably develop more rigid understandings of the world and society. There's little there that means you are less creative; quite the contrary. But, maybe it's less likely you are exercising it. There are a lot of misnomers out there these days, and the understandings are not found where they should be (like art school).

The point about process is one of the hardest parts these days. Rare alternative art histories offer radically different interpretations of creativity, and they are usually more archaeologically/anthropologically sound as well. Either way, our hurdles are related to many modern cultural trends like habitual idolization, genius fantasies, missed relationships with time and presence. It's a hard one and I have struggled with it a lot, so know you're not alone. The reality is that art is so rarely abstracted in the mind devoid of medium and time. Art is an interaction with materials and process BUT NOT an obsession with them. Obsess on other things. The gap in the middle harbors what we call the creativity. If you don't maintain the boundaries, you won't maintain the gap. Or, if you focus on creativity, you're missing the point and just getting older.

Good luck!!! Oh and put yourself into art history because it's all interpreted anyhow. "We don't know! Let's find out!"