How much time people spend thinking about sex can depend on a lot of other factors....such as their age, the general situation around them, their family life, how busy they are with other matters (like work or survival), and so on, and so on.

If you have a lot of spare time on your hands, you are more likely to think about sex, right? If you're a teenager who is longing to investigate the mysteries of the opposite gender, then you will probably spend a huge amount of time thinking about either sex or romance or both. I know I did. If you've been married for 25 years and you're busy with a career then you'll probably think about it a lot less...depending on the career, of course! (Hugh Hefner probably almost never stops thinking about sex...is he still alive?)

What people are really driven to thinking about all that stuff for is the need to somehow to fill that sense of emptiness that keeps gnawing at them. They try and they try to fill it with sex, food, activities, entertainment, gossip, vendettas, arguing on internet forums, being obsessive about their dogs, their kids, their hairdo or whatever....but they never really succeed in filling the emptiness that drives them.

And that, my friends, is what makes capitalism function so effectively. Absolutely deadly. ;-) And it's why advertisers use sex as much as they can to sell stuff too.

It's true that men, on average, think more about sex in a sort of general literal way...but I think women, on average, think more about romance and relationship in a more specifically personal way, focusing on particular people they're hypothetically interested in...so there's the balance. And an awful lot of women love being matchmakers for other people. Very few men could be bothered doing that or would even think about it.