It was always easier to screw up somebody else’s spell than it was to cast one yourself. That was one of the many small unfairnesses of magic. - Lev Grossman

The war we are losing is with time.

But now that the ripened fruit of all that preparation was right in front of him he suddenly lost any desire for it. He wasn’t surprised. He was used to this anticlimactic feeling, where by the time you’ve done all the work to get something you don’t even want it anymore. He had it all the time. It was one of the few things he could depend on.

As he got deeper into it he began to run into a lot of mathematics, which he had to work out with a pencil and paper—you couldn’t do magical equations with computers, they just spat out inconsistent answers before hanging completely. Magical math had to be thought through with a brain.