Some things I'll never get into - personal resonance is still very relevant and important. For others - there could be something there... it would also mean a lot of effort and time in learning about the business, industry, its customers, everything about it I can. Enough to be an expert maybe, certainly enough to be dangerous!
I get extreme joy when I learn about some area I know nothing about. I look stuff up in books and on the internet, I talk to experts, customers, advisors, and others in the industry. I may even visit places where the product is sold, or where the pain point is felt. My team's research department pulls up every shred of info on a subject and I devour it all.
Then, this is most exciting to me - making a monetary bet in that area in a company and knowing I made the right call if it exits. Unfortunately, the chance of a successful exit is pretty low at early stage but I am still left the knowledgeable I've gained which is satisfying and, I'm sure, will prove useful in the future.
There are many in my field who say to never invest in anything you know nothing about. I would say that is true, except that it leaves out the part about going out and learning about that thing that you knew nothing about. It is disheartening to see that many investors stop learning or become lazy and lean on others' expertise.
To me, becoming a jack of neverending trades is one of the best things about being a startup investor.