Rainbows and Semen
Life is a rainbow; it comes spontaneously and leaves in an instant.
These things are only really dumb until you sit and ponder them. (You can tag me in one that is actually dumb if you want to prove me wrong. I'm always game to read that.) If you look at life as a definition, it is like a rainbow. There is a biblical reasoning for having it and a scientific one, and though many would say that the two aren't connected, anyone who stepped back could see the relationship. Rainbows are made when light hits the water in the air (like after a storm) and Noah and his family had just rode an ark after forty days and nights of rain. (You can thank all the religious challenges for my religious undertones here.)
When looking at life, the chances of a life actually coming to fruition, being viable, surviving through infancy and making it to adulthood to procreate and create more life is actually really slim. Every living thing, from your best friend to the tree in your yard to the virus that attaches into your lungs and starts using your cells to make its children, beat some odds to be here. The chances of you being a cum stain on someone's sheets or being attacked by your mother's body or dying before the first trimester are so high that we should act as if every person is a rainbow; celebrated when it's here and lamented when it's gone.
Though by that logic, life can be like a cum shot, which is a MUCH better metaphor. It's going to come since someone worked hard to make it happen, but we have no idea where it'll land or what happens after that. Sometimes it's an accident, sometimes it happens in the wrong place at the wrong time, and sometimes it creates more life.