Maybe a weird place to start reading Sanderson's work, but the title instantly enticed me. And yeah, TFWIHFSME (what a way to shorten that) is a pretty sweet read.
It's not anything incredible or life-changing, but the concept is well thought-out. There's a futuristic and historical aspect to this, which are blended together very neatly. Sprinkle in a bit of fantasy, and yeah, medieval England with guns seems about right.

Pacing-wise it's a bit off in the first half, outside of the main character most people get pretty surface-level characterizations but there's enough witty writing and humour here to keep the book an entertaining read.