Just a point. Nobody any age really wants to aim big. You'll often have to go at it yourself and in your pursuits make the "big" seem more surmountable. That's when they'll want to tag along.
every project falls well short of its goals. if you aim really big, there is a much better chance that there will be something of real value in the parts. a half-baked mvp of a tiny idea is almost always worthless.