How do you stay motivated when you see your idea executed by someone else?

I often think of an imagined solution to an imagined problem and promptly get madly excited about it. The first thing I usually do at this point is check domain name availability. The second thing I do is look for websites/apps that already implement this solution.

I explore the websites and find places where I can improve the UX, add features, etc., but my excitement vanishes the moment I see a moderately well-executed solution. My thinking goes like this: even if I do start working on this and get somewhere, they'd always have an edge over me since they've already learned so much about this space and (gasp) have real users, so I don't stand a chance.

Am I simply lacking in coming up with ideas/solutions, or is this a barrier I should somehow break through? What do you do in similar situations?