One of the keys to success is passion. If you care about something or want it naturally you won't need to force yourself to work on it. The passion will be your fuel. Only work on things you are passionate about.
Regret nothing. OK, well. wait a second. except perhaps, that time when. No, this is good advice. No regrets make tomorrow a better day. Unless you just woke up and need to accept that today is tomorrow. Come on better day!