It's like the difference between between reproducing a proof from a math textbook and actually proving a new theorem yourself. The latter takes a lot more time and effort, even though the amount of work in both cases looks the same from the outside.

(I'm also 39. You and I may see each other at the shuffleboard court soon.)

"I already have it."

The diagonal elements of matrices have a lot of rather "magical" properties if you think about it. Their sum is also the sum of the eigenvalues of the matrix. And if you have a matrix A that is singular, you can choose any value x that is not an eigenvalue, and then A - xI is invertible but still mostly behaves like A.

As a bonus, when I was finally put into the system, they managed to get my zip code, phone number, and SSN wrong. At ADP, quality is job zero.

I smell a sequel to Hamilton.

IME, the Internet was much cooler when it took real-life things and improved upon them. If you're a writer, you can post something on a blog, and now potentially anybody in the world can read it. If you like to play chess but you're in an isolated area with few other players, you can go online and play on there. If you have kids and you want their grandparents to see how they're growing, you can send them the pictures online, etc., etc. But so much online activity these days is only about itself, and it turns out vapid and pointless. Manufactured outrage on Twitter, "lifestyle" pics on Instagram, political battles with your cousins on Facebook, etc. really add nothing to anyone's life. And these things only exist because the platforms are there to provide a place for them. No one walks down the street looking for strangers to argue with, or holding pictures of food to show to people. I hope we, or at least the younger generations, will eventually see Twitter and Facebook and the rest for the wastelands that they mostly are. And I hope something else comes along that lets people actually hear each other, that magnifies good ideas, and that rewards effort.