How about a cap haunted with OCD?  One of eight identical caps.  No, really.  They were $2.50 each at a Florida Walmart and I bought one and really liked it, it fit my scull perfectly with no gaps or puckers.  So I went back and got seven more expecting to toss each one when it got dirty (kind of like a "hat napkin.")  But I would start wearing a new one before the previous one's time had come, and I got out of synch and couldn't throw any of them away.  So now I wash them in the laundry.