How do I cite this John Lennon quote? MLA formatting?

“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.” - John Lennon





I've found the quote all over the internet.. but how would you cite this in MLA formatting? I can't seem to find a direct source other than it came from John Lennon himself.