Larry PortTrying to raise kids and live responsibly amid an onslaught of nonsense.

Here’s something you can use at your next dinner party: it’s a little mathematical oddity that surprises most people. It’s called the Birthday Paradox.

The question is this: how many people do you need to have in a room before the odds are greater than 50% that any two of them would share the same birthday? You’d think 183 or so. But in reality, the answer is 25.

You only need 25 peeps in a group to guarantee more probability than not that any two of them share a birthday. Once you get 40 peeps, the odds are overwhelimingly in your favor.

I’m not going to get into the math on this. But to give you a general sense of how this works, draw a bunch of dots on a piece of paper. Then connect each dot to each other dot and you’ll start to see a whole lot of lines. Now imagine those dots are people, and the lines are birthday comparisons.

To truly understand this, look up Birthday Paradox in Wikipedia or find a discrete math book.

The Birthday Paradox is predicated on an even distribution of birthdays throughout the year, which is not the case. There are more people born in November than April, so the odds are actually higher that you’ll find a match.

I point this out because I don’t think we realize how much of our lives is dictated by probability.

Coincidence? I think so.

In November we got an adorable Havanese puppy. The good news: he’s alive and thriving, though soon to be separated from his gonads.

The bad news: a week later, with the kids at the pet store on a supply run, we impulsively bought a Tetra fish and named him Rudolph. Bad idea, though in theory, it’s a good idea, much like a picnic. Tetra fish are pretty little goldfish-sized fish that need their tank cleaned once a week and need miniscule amounts of food every other day.

So last week I was traveling for work, and no one remembered to feed Rudolph. When I returned, he was no longer blue, but green. And apparently, the broken window theory applies to fish as well. Once you forget to feed a fish for a week, you keep forgetting until they die.

Don’t buy a Tetra fish unless you’re ready for the guilt. You’re supporting “BigPet” and you know in your heart or hearts that the fish is gonna die and it will be your fault.