People don't set out to do things that are hard.

Usually they don't. It's not normal behavior. People do things that are easy, and if they set out to do something difficult, they take it in small, manageable chunks, in an effort to make it easier.

This is why I have trouble when people come to me with great ideas. The better the idea, the harder it's apt to be. I tend to err on the side of telling people to "go for it" even if it seems that they have a massive struggle ahead of them. Sometimes I feel as though my encouragement is "puffing", or at best it's a lie of omission, but we only start things when we've tricked our brains into thinking that it will be an easy task.

I really think that good ideas need encouragement, and not a reality check. Let reality check itself.