Bill and Steve are enjoying a beer and discussing the possibility of love. "I thought I was in love three times," Bill says.
"Thought?" Steve asks. "What do you mean?"
"Three years ago, I cared very deeply for a woman who wanted nothing to do with me," Bill says.
"Wasn't that love?" Steve asks.
"No, that was obsession," Bill explains. "Then two years ago, I cared very deeply for an attractive woman who didn't understand me."
"Wasn't that love?" asks Steve.
"No, that was lust," Bill replies. "And just last year, I met a woman while I was on a cruise. She was gorgeous, intelligent, a great conversationalist and had a super sense of humor. Everywhere I followed her on that ship, I would get a very strange sensation in the pit of my stomach."
"Well, wasn't that love," asks Steve.
"No. That was motion sickness!" Bill replies.