I was told today by my boss that I'm doing exceptionally well and that he wants me to move into engineering when it opens up

This made me wonder how well a person can succeed at things you enjoy doing just because you enjoy it, even if they don't come easy. Also, why are people sometimes good at things they don't neccesarily love. Well anyway, it felt good to hear that from my boss. I was starting to think I was losing it there for a little while. The good vibes were inspiring. Let me ask a question.
Have you ever had something that was difficult to you become your favorite thing to do? Also, has anyone found out they were really good at something they didn't care for.