So why did it take so long for someone to try it?

It’s just as arbitrary as any other number. You can pick at random, but starting with a dictionary attack of easy, non-random keys would probably be a better start.

I remember playing a game of dvd-deal or no deal, where you would pick random number from one to twenty and see if you won money. The people I was playing with were mad because I just started guessing 1, 2, 3, 4…

I told them statistically it was just as likely to be those numbers as anything else.

I think their analogy is still good. Just add "...and your door opens onto Times Square."

That doesn't quite get the full scope, but it does imply the danger pretty well. Plus, if you add in "...Times Square of robots, and the robots are all thieves, and your most expensive possession is visibly sitting right inside, and..." it starts to get pretty unwieldy.

It does doesn't it?

The higher the number of bits, the more entropy in the system.

No it absolutely does, the method they used to generate private keys ended up having just 8 shannons of entropy which led to the discovery we are discussing