A journey that rockets me back and forth between my days learning calculus and the modern career I am building leveraging it. It seems like only after a period away from dedicated study that I could come back and appreciate the wonder of the ways calculus was discovered and fought for. This book chronicles a map of calculus with a forward (differentiation) problem and backward (integration) problem and why they came about.
Strogatz also writes with a curiosity and energy that is fun to dive into (and makes it sure to not be like a textbook).
If you are someone who utilizes calculus in some tangential form and have not revisited the history and origin of calculus since grade school, this is the book for you.