Before you call it impossible, check whether you just mean unfamiliar.

Unfamiliar and impossible feel almost identical from the start line. Anything you have not done has no handholds in it, no sense of how long it takes, no memory of having managed it, and your mind reads all that blankness as evidence against you. Most walls turn out to be first attempts. Telling the two apart costs nothing and changes what you are willing to try.

Take the thing you have written off and ask whether you have really tried it or only looked at it. Spend twenty minutes on the easiest part. Then decide, with something to go on.