How I can prove PMS is real!

I have had approximately 424 periods in my life. But somehow, each month I am surprised by this PMS thing. I don't even honestly realize it until day 2 or 3. So how can I prove that PMS is real?
Because for 28 days of the month I live with a small kitchen. For 3 days of the month I live in a kitchen where people are intentionally standing in front of drawers and dishwashers and purposely on top of me.
For 28 days of the month I wish Lily would put her bangs back in a clip. For 3 days of the month I can only stare at those bangs....I see nothing else....I will beg, plead and bribe her to PLEASE FOR THE LOVE OF MAN KIND PUT THOSE BANGS BACK IN A CLIP.
For 28 days of the month I eat fairly horribly. For 3 days of the month, I eat like a kid their first week in college.
For 28 days of the month, I am with it during the day...not like I am doing aerobics mid afternoon, but at least awake. For 3 days of the month, I walk around in a coma blinded by headaches and counting the minutes until I can sleep again.
For 28 days of the month, I am productive. I get stuff done. For 3 days of the month, I look around not knowing what to do when or how. I am confused, boggled, overwhelmed and therefore do nothing. It's so bad, I can't even imagine I will ever be productive again. I believe my only solution is naps and ice cream.
For 28 days of the month, I make dinner. For 3 days of the month I wander around my kitchen trying to match ingredients but never managing much more than cereal.
But to fully bring this point home, today after school Lily said words I had been dreading. "The science fair is coming up". OH NO. I HATE SCIENCE FAIRS. If this would have come on any of those other 28 days I am guessing I would have been cringing but might have had some level of restraint regarding my own psychosis. But today, one of those 3 dreaded days, I just couldn't bear those words. The Science Fair. For days I had been hoping that neither one of my kids finds out about the science fair. I dread, hate, fear the science fair. Both girls have done plenty of science fairs and I am fairly confident neither one remembers anything about what they learned. I think they remember the actual fair and how fun it is running around with all of the kids. But I am certain they have zero memory of the pain and agony that came before those glorious moments at the fair. So when today, Lily said "Andrea and I are doing the science fair together", I nearly fainted. I just said "nope. We aren't doing science fairs this year". I could hear how that sounded and I think I was actually moaning when I said it. Probably even whining. I felt badly that she felt badly but not today, not now. I HATE SCIENCE FAIRS. So there you have it - proof that PMS is real. When a rational intelligent mom tells her enthusiastic 3rd grader "no way" to an American past time like the science fair, we have proof. It's real.