No one is listening until you make a mistake. Not one shred of evidence supports the notion that life is serious. Nothing is a waste of time if you use the experience wisely. Nothing is as inevitable as a mistake whose time has come. Nothing is ever so bad that it cannot get worse.
Nothing is foolproof due to the ingenuity of fools.
Occasionally you will stumble over the truth, but most of the time you will pick yourself up and go on. One man's curse is another man's blessing. One seventh of your life is spent on Monday. Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. Opportunity always knocks at the least opportune moment.