When partnering with Kent Beck, most everyone has this experience: Something goes wrong. The code doesn’t work. You start to think: “What could cause that to happen?” Kent doesn’t think about what the problem is. He just sets a halt in the system and lets Smalltalk tell him what the problem is.
Sometimes you’re right about what the problem is. If you’re really quick you’ll be able to tell Kent what to edit in the window he’s already looking at. If you’re really quick.
Sometimes you’re not right about what the problem is. Forget it, he has already fixed it. Train yourself to think about where to put the halt, not to think about what the problem is. Of course it’s a great feeling when you can reason to the problem. But we’re not here to make our brains feel good, we’re here to get the code working as quickly as possible. Setting the halt and letting Smalltalk tell you will help you build working code faster.