Wikipedia defines common sense as “knowledge, judgement, and taste which is more or less universal and which is held more or less without reflection or argument”
Try to avoid using this topic to express niche or unpopular opinions (they’re a dime a dozen) but instead consider provable intuitive facts.
Another variation of that is claiming how getting sick repeatedly is somehow beneficial for getting a strong immune system. That ignores research, as children who have a lot of common infections early in life have higher risk of moderate to severe infections and antibiotic use throughout childhood. That also ignores viruses for which a durable immunity isn’t currently possible, such as COVID.
EDIT: Basically the immunity system doesn’t work like a muscle.