@igobydani May I share a comment Dani? Just listen and try to understand. Defending one's opinion, like in your grandpa's case, will take a lot of time to change. Try to share that this could be a both/and situation, which may help him to think about his position and not just defend it.
@bgillie1 Does you motion sickness get worse after eating certain foods? You might have reactions to medicines or food. But if it is consistent you might have an ear infection or be developing an inner ear disorder like Menieres Syndrome. Keep us informed for prayers.
@bgillie1 Is how we store things in our brains. It's all about storage and retrieval. It's like filing things in a cabinet or drawer. Develop a system that works for you. Research storage and retrieval.