Every day is like a day at the beach; tide comes in and washes the all the crap away leaving clean sand behind. If you think I'm wrong and ask what about the rocks?  I say watch the rocks, they all disappear after a while, some hold out longer than others but they all get cleaned away in the end.

Now think of yourself as the ocean cleaning the detritus of the day away each and every day.  Sometimes like the ocean you give a lot some times you take a lot.  At other times you have stormy days/ calm days, in the end none of it really matters because you have the strength to wash away the sand castles of the petty and small.  As for the harder rockier problems in life don't try to smash them unless you have unlimited rage to smash them apart in one go, instead do as the waves do and slowly nibble at them and wear them away to nothing.

So really the only thing to remember is that all problems disappear sooner of later when the tide comes in.