People value intelligence and will apply that label to themselves even if it may not be true. It's a hard thing to measure though IQ does it reasonably well. To those who have a high IQ: what is it like? Can you pick up any book, read it, and understand the gist with minimal repetition? Can you infer solid and accurate conclusions based on a small amount of evidence? Is any subject or discipline up for grabs or do you have to have a keen interest in a particular field in order to flourish? What is something you are able to do that you know is because of your intelligence -- the proverbial 1,000 pound deadlift of the brain, if you will.
There is no point to these questions other than curiosity.
IQ is general intelligence. That's why you would have to not talk with him about anything else. And it's also why IQ tests include a variety of questions. You can also test IQ in ways that are very difficult for an ordinary guy to train, like the highly g-loaded reverse digit span.
Street smarts is just 'wisdom', not intelligence. If you grow up sheltered, that does not actually decrease your intelligence, it just makes you incapable of dealing with anything.
If you brag about it online, it really is. It's not an honest signal, of course, because whether you score 80 or 150, you can claim to be 150.