At least once every year (and by once I mean 6+ times per year), I am convinced I need a bob again. Logically I know that every single time I've bobbed my hair the enchantment lasts a week. Then it starts growing in like Moncchichi hair and I have to get it cut every 4 minutes so it doesn't grow out weird and start getting flippies. Within the first month I get pissed off that you can't do very much with a bob. (Never mind that I almost eternally have a ponytail. That is failure on my part but I could have more than a ponytail.)
Additionally, it's really hard to grow in a bob without some awkward as heck hairstyles.
And for all of these reasons, I will not have a bob. Won't.