What immediately comes to mind for me:

You are knitting a fitted garment. Let's say it's a sweater. You've been knitting for awhile, and you''re starting to get concerned it won't fit the intended recipient. You can't tell for sure, because your needle is too short to fully stretch it out, but you just have this feeling. This feeling you hope is wrong, because you don't want to rip out and re-do all the ribbing you've just knit...