Rileyl that is a very interesting theory you have going there it actually makes sense to me. My DH vomits alot due to an overactive gagreflex and acid reflux issues and he vomits like it's nothing, he is so used to doing it, it's as normal to him as waking up and brushing your teeth and then going about your day. Ihardly evervomited as a kid(3x throughout childhood that's it) but alot of people around me did-my cousins seemed to always have tummyaches/vomit from eating too much junk food or overeating at gatherings and my mom, grandmother and a couple of cousins suffered from motion sickness.