Scott Young has an great entry on Enthusiasm.
Enthusiasm is like any other skill. If it is continually practiced and exercised, it gets better. If it is not, then it will atrophy. Enthusiasm rarely comes naturally and it must be the result of conscious effort. Practicing the ability to use enthusiasm can keep you excited and driven even in horrible circumstances. Without this ability even great circumstances are viewed through the lens of sarcasm and cynicism.
Genuine enthusiasm can only be sustained about something you are truly passionate about. Anyone can get themselves hyped up over a boring situation for the moment, but sustained enthusiasm can only come when you deeply care about something. If you aren’t that interested in the outcome of something, you won’t be able to create enthusiasm.
Don’t spend your time pursuing things that you aren’t passionate about. If you aren’t passionate about something, try to minimize or remove the time it is taking from your life. Nobody is going to applaud you for working at a boring job, having boring hobbies or staying in a dead relationship when you are dead. We are ultimately responsible for the amount of passion we experience in our lives.
If you look at really successful people, all of them having something they are very passionate about. These people have a drive that compels them to give 110%. Nothing is more motivating than an obsessive passion. As a self-proclaimed obsessive about personal growth, I can attest to that.
BOTTOMLINE: Common sense? Perhaps. Insightful? You bet! Keep in mind - Scott Young - is still in high school. How about THAT for enthusiasm and passion??