I had to rip back a finished hat last night. Why? Because it turned out that the hat was too small for my head. Mind you, I followed the instructions perfectly. I worked 13 rows of the ribbed brim, then switched to stockinet to do the rest of the head until the whole thing measured 5" from the edge of the brim, and then I began the decreases. But still the hat didn't fit! I ended up measuring my head and realizing that I needed another 2".
My mother had suggested that I just pick up the stitches from the brim and work a few rounds downward so that it would still fit but I wouldn't have to unravel the whole thing. It sounded like a brilliant idea, but honestly I didn't want to be bothered doing that (do you see my logic here? 'cause I kinda don't). Plus -- in my defense -- had I just worked from the brim down, the button that went on the hat would have been completely off center, and to make it look good again I would have either had to undue the button (a hard thing to do when one can't find the thread anymore one used to fasten the button), or buy a second button and put two on the hat (another hard thing to do since there was only one of those buttons left in the bin.
On the bright side, the yarn is a alpaca/wool blend, so I could do that spiffy little end-fusing thing. Never have I had more fun spitting into my hand. xD