After his father's death, he was 11 in 1983 when he got his first guitar, which was a blue stratocaster as a present. The first song he wrote was called "Why do you want him" and was written when he was 14 in 1986.
In 1988 and 1989 Armstrong formed Green Day and The Sweet Children and started touring for the first time.
Armstrong got married In July 1994 to Adrienne and has two children Joseph Marciano (born March 1995) and Jacob Danger (born September 1998)
He is also the co-founder and partial owner of the independent label Adeline Records.