2. "Imagine." Lennon's 1971 single "Imagine" is considered one of the greatest songs of all time. The song's lyrics promote peace and unity, and it has been covered by numerous artists.
3. Activism. Lennon was a vocal opponent of the Vietnam War and other political issues. He was also a supporter of the Civil Rights Movement and other social justice causes.
4. Personal life. Lennon's personal life was often in the spotlight. He married Yoko Ono in 1969, and the couple's relationship was often controversial. Lennon was also known for his drug use and his struggles with mental illness.
Lennon's death in 1980 at the age of 40 shocked the world and left a lasting legacy. He is remembered as one of the greatest musicians and songwriters of all time.