I found one image with John Lennon’s quote. I think it’s a pretty damn good quote, and totally pretentious of course.
“When I was 5 years old, my mom always told me that happiness was the key to life. When I went to school, they asked me what I wanted to be when I grew up. I wrote down “happy.” They told me I didn’t understand the assignment and I told them they didn’t understand life.”
At the end all that matters is how happy you were, how much you loved and how much you were loved.