Mars buys 2 in 1

Of the multitude of differences between men and women, I think one of the more amusing is how we buy hair products. Women you see, buy shampoo and conditioner because they serve two completely difference functions, both of which are equally important. Men on the other hand pick up two-in-one shampoo/conditioner and think "what a great idea!" Then they wonder why women would ever buy two products when one does the same thing?