Not all women want jewellery or flowers as a present. Some women like other things far more and would prefer it if you spent your money on something that actually pertains to their personality, and that shows that you have a sense of who they are.
High heels are a living hell. Truly torture. It is kind of shit that it is an expectation that women should wear them to formal events/in the office.
Women can like 'manly' stuff without it being insincere.
If you are a woman who likes masculine things you will be berated by other women quite often.
There is no way to truly describe the immense discomfort of having your period when the weather is humid or hot.
There is an immense pressure to be both curvy in certain places and a size zero. For a very large percentage of the female population, this is not genetically possible. It is hurtful when men constantly seem to idolise a body type that can't be accomplished.
There is an expectation, on dates or in social situations, that you shouldn't eat all that much. Women aren't supposed to order a rack of ribs entirely for themselves, even if that is what they would want.
If you are a woman who doesn't want or particularly like children, people often treat you like you are somehow deficient or are secretly a bitch.
You will always be expected to clear the table, do the dishes, do the laundry, cook etc etc and you won't often be thanked for it. This isn't just something that is imposed by men, women expect it of each other. If a man helps clear the table he gets to be a really nice guy, but if a woman refrains she is an ass.
Make up is still considered a must in most work places, even if it isn't stated. It kind of sucks that you have to spend money/time on make up just to be considered professional enough to walk into the workplace. Even if you have really good skin and don't actually need to wear it, unless its for fun.
If a man is staring at you, walking behind you at night, hits on you and won't go away etc you always have it in the back of your mind that you need to be careful and you might be attacked. It is unfair for everyone involved, but all women worry about it. It is often why they go to the bathroom in pairs.
If you are in a group of guys and they make negative comments towards another woman, in order to impress you with humour or to I don't know, be cool, every single woman in that conversation is thinking that you are a dick. They are thinking it while they pretend to laugh.
Handbags have everything you could ever need in any situation tucked somewhere within them.
Gentleness and respect towards women, in a man, is an immediately attractive feature that can take an average looking guy up quite a few notches.