Technology guru Danny Goodman did, and with this book he leaves a well-marked trail for you to follow.
He introduces Objective-C and Cocoa Touch in a context you'll readily understand, and shows you how to test iPhone code snippets as you go.
Why bother with Apple's tools? After all, you could bypass them and just build web apps for the iPhone.
But web apps can't access an iPhone's music library, address book, camera, accelerometer, or multi-touch events.