I have a pea head. When I was in college, my friend from Trinidad told me one day: "Girl, you have a head just like a ripe mango." As a result of my head's apparently diminutive size, I don't own any hats other than a plethora of tight fitting winter toques and one fuzzy cloche that eliminates my peripheral vision.
My whole adult life I have been on a search for a baseball cap that does not look ridiculous on me, fall down over my eyes, or get a stupid-looking poof at the back from uber tight adjustment. I would dream of being able to leave the house without washing my hair -- hey, I'll just slap on my cap!
I had come to grips with the reality that I would probably never have a properly fitted baseball cap, but Pete refused to accept defeat. From time to time, he'd sneak up behind me and encircle my head with kitchen twine, ribbon, etc. to later be measured to determine my cranial circumference. His conclusion was that I would require the elusive XXS.
Red Sox Team Store at Fenway. After decades of searching and a well-spent $30, I have my hat. Oh, XXS, you are so wonderful...