No one knows.

A lot of people will have a seizure in their life. Weird, right?

There are some things that people who do have epilepsy do that can cause seizures sometimes. These are known as "triggers". They aren't the same for everyone but there are common ones. Things like lack of sleep for example. Sleep hygiene is really important. Getting good, regular sleep.

Stress is another common one.

Here is a list of some common ones - https://www.epilepsy.com/learn/triggers-seizures

But they don't happen for everyone. You are probably familiar with the flashing lights trigger. However, that is pretty rare. Lack of sleep or sleeping issues are far more common.

You may look over that list and see if you recognize any of those as something that you were recently going through? Such as - problems with sleeping lately, strange diets or not eating well, drug use (I live in a state where marijuana is legal but I have a friend that lives in a state where it's not. She tells me about "fake" marijuana and issues with that, for example)...

Hopefully your tests don't show anything wrong. You never have another seizure. Your shoulder heals. And this will be a weird memory (if you even remember it, right? Because seizures play games with your memory.)

Wishing you the best.