Lennon was a crappy person...
- Whenever he saw a crippled or handicapped person, he would shout stuff like "Freak!" and reduce the person to tears.
- He was a crappy father. After he and Yoko got together, he completely ignored his first son Julian. It got to the point where Julian, as a child, asked his mom Cynthia (John's first wife), "If dad is always singing about love and peace, how come he hates me?"
etc etc.
Marami pa, you can read about the things he did in any Lennon biography. He was a troubled person but a great, great artist.