What are you emotionally invested in?

[Sabre]

I was talking to a guy today who seemed pretty rational. We agree on almost everything, he has some interesting ideas. I've mentioned him before. Today we had our first disagreement. He has a health condition and as such researched the topic quite alot. Today we were talking about health I pointed out a flaw in his logic. I assumed he would either correct me, his argument, or discount his point.

Instead, he started calling me names by saying my understanding was weak and I should do my own research if Im so smart. I came to the conclussion that even ration, science based people are invested in something. For me, it's probley games.

What are you so emotionally involved with that nothing but the most extreme, unrealistic amount of evidence and experience could convince you otherwise?