Personal Baggage ?
 

Why do women insist on hand bags and men on pockets?

Because women don't want bulging pockets. Imagine what your pants would look like (and your thighs) if the pockets were stuffed with lipstick, comb, keys, wallet etc. (there's a lot more than that in my purse -- eye drops, and indispensable "stuff").

Men don't carry as much and don't care what their pockets and their thighs look like.

It is the custom.

My mother always had to carry all my Dad's things in her purse.

I think ultimately it stems from the fact that women require additional personal items once per month and so we need a place to carry them with us. Thus we've evolved to carry all such necessary personal items discreetly in a hand bag.

Does that answer your question?

Don't forget cosmetics.

Because most women's clothing does not have as many pockets! And, most of them are not deep enough (items fall out).

This is why I favor LLBean slacks, raincoats, etc., for traveling. The slacks have very deep pockets (the microfiber with a hidden zipper pocket) and the raincoats have lots of useful pockets. I always take my raincoat on the plane, for the pockets, and because planes are often chilly and I'd rather snuggle under my raincoat than one of those airline blankets.