I thought the same and even told my boss "Oh, I really doubt I'll get selected", but then not only was I selected out of the first round (despite going through like 80 people in the 120-person jury pool), I ended up as foreman.

They're selecting for neutrality. What both lawyers and the judge all want to see is someone who doesn't have an opinion on the case before it begins. That neutrality could be a product of them being easily swayed by arguments, or it could be someone who is coldly logical and makes a decision purely based on the evidence presented.

I watched about 65 people get dismissed, and what they all had in common was they were visibly emotional before the trial had even begun. That is what gets you dismissed. Meanwhile, about half the folks in the jury box didn't even realize that the fact that we were still sitting in the jury box meant we would probably be serving on the jury, we were still like "Oh, I'm probably going to get dismissed because I'm X kind of person and the lawyers aren't going to want X kind of person." If you can think of it that dispassionately, you are the type of person the lawyers want.