Side note: as is often my practice with Google, I like to watch the toolbar to see the many trajectories my education could take on its way to my final search term. As I wrote "time of year most..." you can see what came up.

Time of year most...
1) Breakups occur
2) People die
3) Babies are born
...Which means, in order, we are most concerned with sex (or potential lack thereof), death, and birth. I'll leave it to you to imbue those results with any further meaning as I can feel myself already getting off-course.
When I finally did complete my search term (I'm a slow typer), the very first result was this article, confirming wherever it was that I heard that statistic in the first place.
If you're now wondering, then, how vasectomies and google searches relate to happiness, or in particular to happiness associated with March and April sports, I'll help you connect the dots. The simple fact that men are actually willing to essentially disconnect the valve on their manhood in large part to have an excuse for a long weekend of watching basketball or golf speaks volumes about the wonders of this season in sports.
Forget longer days, fresh air, and birds chirping. The real testament to the power of spring is a the fact that men are willing to go a painful outpatient procedure just to enjoy the sports of the season. Snip, snip and happy watching.
...I wonder if Tiger had one too?