I have big feet. REALLY big feet. Depending upon the brand, I wear either a 14 or a 15 sized shoe. That's big. I wish I was as big, proportionally speaking, as my shoe size, but I'm only 6'3". Oh well.
I once met Luc Longley when he was attending UNM, who played in the NBA after college, and is 7'2". He had about the same size shoe as I do.
I have two sisters from my Mom's first marriage who are 9 and 11 years older than me, respectively. Once, when I was five, the younger of my two sisters borrowed my tennis shoes. They fit her perfectly.