Almost 10 year old mikes hard lemonade-how bad can it be?

My dad had a case of mikes hard in his basement, so I helped myself to one last week. I ended up getting a weird headache after and felt woozy. I’ve had plenty of mikes in the past and don’t get headaches from alcohol unless I drink a lot.

I recently had to toss a can of chili he had in the basement since the expiration date was from 2012 (and it was rusty) and there were quite a few other cans that are past their expiration, but not nearly as old. So out of curiosity, I looked up the batch number on the mikes and found out they’re from 2015.

I told my dad and he said he had one the other night and it was fine and now he’s drinking another as I type this lmao. I know alcohol itself doesn’t really go bad, but what about the rest of the stuff in these? Is he gonna die? Jk, I know he won’t but I’m curious if my headache was actually related to drinking this decade old sugary drink.