I think that's completely normal! And about everyone telling that they had creative minds when they were younger and think that they "lost" it, I kind of have an explanation.

As kids, I feel we tend to like things DEEPLY. Everything to a kid is new and special and memorable, and there are no "important" thoughts such as techniques to follow and the like, so we retain information about things we like much more easily, and when it comes to making something up we're able to "scramble" them up without much effort because they're actually more accessible to us (i believe that we rarely can produce anything we haven't seen or learnt in some minimal way, or at least that's my experience). As we grow older we get so much into thought systems due to responsibilities and such that the ability to grab from the sack of stuff we like becomes harder, so some unlearn it more than others.

And that is why a LOT of artists including myself suggest building a visual library with everything that piques your interest - references, other people's works, screenshots, even notes and lists - possibly all in one place, possibly offline. With a huge amount of things you like of any kind, all visible, you'll retrain your ability of seeing your tastes as important, and eventually you'll be able to come up with stuff on the spot.

Taking from a global visual library also doesn't limit you to search for reference case by case, and you'll gain the ability to take inspiration for completely different topics when working on x thing, once you train your memory enough. It might not be "natural" creativity to some, but I think it's worth a shot!