One more makes..."a lot"

Last week my dad had another stroke. My mom and I can tell what he has lost as far as mental and physical abilities. He is not as coordinated at fine motor skills as he was even two weeks ago and he is having trouble where he switches words around and his sentences come out confusing everyone.
When he was taken in to the hospital with this last stroke, as this one was accompanied by massive amounts of pain, he was given an MRI. When the doctor came to admit him to the hospital my mom asked if the MRI showed anything, and the doctor replied "Just that he has had a lot of stokes".
That's as close as anyone can come to a number, no one really knows how many he has had. When he started having them, or how many he has at any given time. I myself have lost track of the ones we have actually known about and had documented by MRI.
Some how, and for some reason, I feel like I should know the number. I feel like I should know how many times this thing has happened to him, ultimately resulting in the disappearance of the father that I grew up with, but in the end the doctor is right "a lot of strokes" is what I am going to have to be happy with because I will never know. There is no way to find an answer.