I don't know what I thought would be the #1 song on the day I was born. I'm a 1984 kid, and Michael Jackson's "Thriller" was topping the charts that year, as was Springsteen's "Born in the USA," and Prince's "Purple Rain." So there are some pretty solid possible choices.
This slightly distressing information comes from Playback.fm, which lets you see the top song on the day you were born. You can search birthdays reaching all the way back to 1900 — Jeff Callahan, who runs Playback.FM, told Refinery29 they had to go back that far "after some complaints from people as old as 97!"
But now that I've shared my birthsong, I'm not just going to let you walk away, just let you leave without a trace. Go to Playback.FM and find out what your birthsong is. They even let you rewind the tape nine months and find the top song on the (approximate) date you were conceived. So there's that.