Just because you don't think it can be done means it's really impossible, not when a roadblock to you is just a small hurdle to me.
It's a bad pet peeve that annoys me so when I hear people say "It can't be done" without even trying to look for possibilities.
Like, so what? It's hard? Then think outside of the box. You want it, right? Find other ways. Unless you've actually put out your best effort and sought ought resources that could help, don't even think of mentioning it can't be done.
Some people face hard things all the time. And guess what? It can be done.