If you go to
http://www.thisdayinmusic.com you can find out what was at number one in the charts in both Britain and the US the day you were born.
In my case it's "Somethin' Stupid" for both sides of the Atlantic, sung by Frank and Nancy Sinatra.
They also suggest (for those born too early) that you can go for your 18th birthday to find out your "life's theme song".
In my case that's "One More Night" by Phil Collins (US) and "We Are The World" by USA for Africa (UK).
Actually I'd rather have either of those than "Somethin' Stupid" as my theme song...