A fox was wandering and came upon a beautiful vineyard. He spots this vineyard and gets very excited to eat the grapes. So he runs up to the tall vines and notices the juicy purple grapes are all up near the top of the plant. He runs to them and jumps, just barely missing the fruit. He tries again, and again. And after several failed attempts to reach them he gives up. "Fine," He says, exasperated, "those grapes were probably sour anyways."
So I completely ad-libbed that story, but I think it goes something like that. My point is, my entire life I have had this fear of being "Sour Grapes" about things. If I didn't succeed, I would insist that it was my fault and beat myself up about it because heaven forbid I consider that it's possibly not a part of "the plan" in the first place. And I understand the concept of never giving up on something, I really do. But some times... in some situations it's okay to give up, I think. It's important to know when to walk away from something.
Like if you LOVE to paint, I think you should do it. And if you're terrible- do it anyways. But by all means- do not become that starving artist who banked everything on your art only to die in the streets. Do not go down with a sinking ship!!