If children were brought into the world by an act of pure reason alone, would the human race continue to exist? Would not a man rather have so much sympathy with the coming generation as to spare it the burden of existence, or at any rate not take it upon himself to impose that burden upon it in cold blood?
People were messy. They were defined not only by what they'd done, but by what they would have done, under different circumstances, molded as much by their regrets as their actions, choices they stood by and those they wished they could undo. Of course, there was no going back - time only moved forward - but people could change.
And for better.
It wasn't easy. The world was complicated. Life was hard. And so often, living hurt.
So make it worth the pain.
This is the key to life: To expect everything to be given to you from above, yet to be genuinely surprised and forever grateful, when they are. Expecting all good things to be yours, while not knowing how to take anything for granted. If there may be a key in life, this is the key.