Ask HN: Should I try to create something that already've been created?

Once in a while, I have good ideas. Normally, they arise from problems I encounter or from things that bother me.

Then, when I get these ideas, I feel impelled to create: I start doing researches on what technologies I'd have to use, which things I'd have to know to be able to start developing... In other words, what will be needed to turn that idea into reality.

...and then, I end up stumbling into a product that has exactly the same functions I had in mind; or, into a solution that pretty much suffices all my needs. And, then, I lose the will to develop my idea.

So, I'd like to know what are your thoughts about this. Should I avoid creating a product that is similar to something that already exists? Should I go ahead and develop it anyway, because my solution could end up being better than the existing?