once every four years

today at 11:59, one minute before i was to clock back into work, my mom called.

"hello?"
"do you know what today is?"
"no."
"well let me tell you, it's leap year. & this day only comes once every four years. today you can propose to a man. this is your only chance for another four years."
"uh huh... well you find me a man & i will think about it."
"I WILL!"

excuse me mom? what is this supposed to mean?