When I was 5 years old, my mother 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.

While commonly attributed to John Lennon, we have yet to find any credible sources to verify him as the author of this quotation. A similar concept appeared in the Peanuts comic strip by Charles M. Schulz (January, 1960). The panels, showing a conversation between Charlie Brown and Linus van Pelt, read as follows: Charlie: “Do you ever think much about the future, Linus?” Linus: “Oh, yes…all the time.” Charlie: "What do you think you'd like to be when you grow up?" Linus: "Outrageously happy!" Additionally, Goldie Hawn is quoted with a similar response in a 1992 interview with Vanity Fair magazine, in which she recalls:

People used to ask me what I wanted to be when I grew up and I’d say ‘Happy!’ That was all I wanted to be.