(please don't fail!)
A manager at a General Store is teaching a young, newly hired boy how to sell people more than they really want. Suddenly, a man walks in asking for a bag of lawn seed. The manager walks up to him and says, "Of course. But you will be wanting a lawn mower, too, right?" The man asks, "Why would I be?"
The manager replies, "Because when the lawn seed grows, you'll need something to cut the grass with."
Surprisingly, the man buys a lawn mower. Then another man walks in and asks for a box of Tampons. The manager nudges the newly hired boy. The boy walks up to the man and says, "Right away, Sir. But, of course, you will be wanting a lawn mower with that, right?"
The shocked man asks, "Why?!"
The young man then replies, "Well, your weekend's screwed, so you might as well mow the lawn."