I feel your pain everyone, and I promise to never make fun of any major! I can't recreate the conversation like some others have, but I can convey in prose some of what has happened to me.
I once had this conversation with a few members of my family who were trying to convince me that mathematics is only useful up to and including basic arithmetic. The older generation honestly couldn't imagine what more there was to mathematics outside summing up the prices of your groceries, or subtracting what you're paying from the amount of money you have and other such life situations where math basically allows you to function. I could see where they're coming from. It would take me a week to explain to them what a function is, let alone calculus or (shudder) modern algebra, and the more I talk about these things, the more they'll think they're useless because they don't apply to their lives in any way.
One of the relatives was a bit more knowledgeable having studies engineering, and he was on my side for calculus, but he thought such things as topology and modern algebra are useless. He told me a story of a mathematician he knew in university who would regale him with stories about the topology of a Luffa. Of course my relative remembered a story where something as mundane as a sponge was involved - "why in the world would you analyze that!"