I think the best way is basically to go after the long term while keeping a positive disposition and doing your best to be excellent at something that interests you. There will be up and down days, but I don't think you base it off of that and instead the overall picture.
For others who start complaining about something not working out for them, it's probably because they are being dumb. If they weren't being dumb, then they would be happy or doing something positive about the situation.
In a nutshell, a person shouldn't be thinking how good he is about something or jump to conclusions right away without having experienced the unknown yet. This is probably what some dumb people aren't able to sense and as a result they end up depressing themselves and staying dumb when they do mess up someday. There are probably also people who want to do something but are just too dumb to get into it.
The only thing I think is acceptable is if the person is truly happy to not get into something for any reason and manages himself just fine. There's nothing wrong about being below standard as long as the person is already satisfied with it.
