Birthdays.

"Wow, seems like everyone has a birthday in November. What's nine months before that? February? Why are people fucking in February?"

"Valentine's Day."

"Oh, good point. It seems like there's that, and then there's a lot of people conceived in the summer. Nice fucking weather in June and July."

"I wonder if we could correlate July conceptions with fenced back yards..."

"Not everyone thinks the way you do, Holly."

"Shame."