All good things must come to an end, but same goes with bad things as well. Come what may, for better or for worse, it simply will not last forever. Endure the rough times and cherish the fun ones. ESPECIALLY cherish the fun ones. Good memories deserve to endure.
Don't let rough spells give yourself reason for an end. Don't take beautiful moments for granted, either. Life is more than endless light or constant darkness. The balance is never even, and some have it rougher than others, but so long as we lift each-other up, we'll be okay.