Don McLean, who wrote and sang the song. American Pie was his first hit, an international success that reached number 1 in the USA and no2 in the UK (in a cruel twist of fate, his all-time classic was around at the same time as Harry Nilsson's similarly all-time classic hit "Without You", and Nilsson got the no1). Perhaps American Pie really did mean that McLean would never have to work again, but if it didn't, his second hit (and first UK no1) "Vincent" certainly did.
It's true that McLean said this but perhaps as a little joke. He certainly has been working, touring and still making albums.
If you want more info on my interpretation of the song, look at my site: www.missamericanpie.co.uk
Enjoy!