Every time I bring up that I'm building an app on my own time, without fail I'm asked "How are you going to make money off it?" People never listen when I tell

Every time I bring up that I'm building an app on my own time, without fail I'm asked "How are you going to make money off it?" People never listen when I tell them that I code because I enjoy it. It makes me wonder how much people actually enjoy aspects of their own lives. If I make money off what I do, that's great, but most of my motivation is to satisfy the "what if" and "could I" type questions that run through my brain.