"Not all Englishmen are magicians. At least in my world, there's only a handful who can do magic to begin with." Himself. Gilbert Norrell. John Childermass. Still leaning back, Strange continues talking.

"I didn't have to become a magician. I could have easily run an estate or become a poet. But Arabella...at the start of things, she seemed so interested in the magic that of course I wanted to do it. She pushed me and supported me while I tried to learn the magic. I did it because it made her happy."

At first, at least. Later on, the magic became more of an annoyance than anything else. But Strange was too much a magician at that point and couldn't be anything otherwise.