"I don't feel like getting up, maybe I'll just cancel my meetings and workouts and sleep the day away."
My second thought?
"You can't be great at something if you only work at it on days when you feel good."
Think about it. If you had a goal to lose 20 pounds, but only exercised and ate right on days when you were motivated or "felt like it," would you be successful? What about if you wanted to earn a college scholarship playing a sport, but only practiced your skills on days when you were feeling good; would it be more likely?
My answer is "NO" to both of those situations.
Almost everyone has goals and dreams they hope to accomplish. What separates "us" (those who read this website and myself) from "them," is how we work towards achieving these goals and dreams. Success doesn't happen over night; it is the result of consistent and deliberate effort towards an established end point.
Hopefully the next time you contemplate skipping a practice or workout session, or eating an entire pint of chocolate ice cream, remember that success in any area is a result from working at getting better in that area, regardless of how you're feeling on that particular day.