I did not own a purse until I was thirty-(delicate cough)
There are a variety of reasons why - there's no point to having a purse when you're already hefting around a book-bag filled with ungraded student essays, library books, notes from the latest grad student coloq, three different kinds of pain killer, datebook, empty coffee cup attached to the shoulder strap, etc.
Then I slowly crept toward pretending to be an adult and accepted that I probably should own one. Truthfully, I'd rather have accepted the need for a speculum, but you don't bring implements to job interviews. I asked a family member with good taste to get me one for Christmas. Said family member (a man, I would note) came through it spades. My one purse is simple, easy to carry, easy to stow inside the inevitable book bag and so far immune to my destructive powers. Jeanne commented that some books fit into the hand or purse, etc. better than others, and that this affects when and how we read them. To my incredible delight, almost all books fit into my purse - big hardcovers are out, but I can still squeeze in almost everything else.
Waiting in line on Friday I read through 25+ pages of a mystery I tucked in there a week ago - The Cat Who Sniffed Glue if you must know. It passed the time and made me far less annoyed - all hail my reluctant purse.