I wish there were some general test you could take that tells you if you differ from other people in a fundamental way like this.

I've heard of a condition that's like "superempathy" where you actually feel the pain you see in others as if it were done to you. E.g., you see someone injected with a needle, you feel as if you were stabbed with a needle. Such a test would tell you whether you have a normal "ick" reaction, or some sort of abnormal ability.