I'll bet I'm not the first one to make this observation, but when one compares women to men, as I seem to do on this site way out of proportion to how much time I spend the rest of my life thinking about it, it seems to me that shopping and sex illustrate in parallel ways how we are different.
Men know what they want and often are very eager to get it over with. They want to get in and out as quickly as possible. Women want to take their time, and enjoy making it last as long as possible.
Though of course one big difference is how much each of us seems to be willing to spend on it.