Michael (as Flea was then still known) led a relatively conventional family lifestyle in Australia until his father Mick was posted to New York in March 1967 in accordance with his job as a customs officer, taking with him his wife Patricia, daughter Karen and the young Michael. After only four years in the U.S., Michael's mother Patricia met and fell in love with a jazz musician named Walter Urban Jr in 1971, resulting in the divorce of his parents. Michael was again uprooted, this time right across America, as his mother and soon to be stepfather moved with him and his sister to live in Los Angeles in 1972.

Michael developed an enthusiasm in playing music very early, first trying his hand at the drums. However, at the age of nine he took up playing the trumpet and soon proved to be a natural talent. He was so skilled with the instrument, that upon his family's settlement in LA he swiftly earned a place in the Los Angeles Junior Philharmonic Orchestra. Already so proficient at playing the trumpet, watching his stepfather jamming with his bebop jazz band had a profound effect on the eleven-year-old Balzary, and this fueled his new-found love for jazz and leading exponents of the genre, such as Miles Davis, Dizzy Gillespie and Ornette Coleman. Concerning his singular love for the jazz genre at the time, Balzary confessed to VH1's Behind the Music that he originally had no interest in rock and roll, and his ambition was to become a jazz musician like his stepfather. He was still (and remains to this day) an avid trumpeter and jazz fan when he started at Fairfax High School in September 1976, but this academic shift also brought about a fateful meeting that would change his life forever.


Flea's bass-slapping technique is unique and was a major influence on other bands even before the Red Hot Chili Peppers broke into the mainstream, which is why, on their breakthrough album Blood Sugar Sex Magik he refused to use the technique in the same way, to avoid it being imitated (As stated personally by Flea in the documentary of Blood Sugar, "Funky Monks"). Flea's style is influenced by Bootsy Collins, funk music and by the energy of early punk rock bands such as Black Flag.