[Error: unknown template 'qotd']Doing what I'm good at. Using my skills. A feeling of 'Oh yeah, I can do this.'

Using your skills, especially skills that you have worked on to aquire, feels good in and of itself. Much in the way that flexing your muscles feels good. It makes you aware of the power they carry. It makes you aware of your possibilities.

Having aquired certain skills, and using them, is one of the greater plesures in life and it's one that I can't remember ever having been told about.

Company logo icon, because 'work' was the first thing that came to mind when reading the question. And that's a Good Thing.