The Solomon Paradox - Why Are We So Good at Picking Other People's Arguments Apart?

We're really good at giving out advice that's very hard for us to actually employ in our own lives. So why are we so good at picking other people's arguments apart and so terrible at objectively evaluating them? In psychology, reason is not the big "R" reason of philosophy,. It's just coming up with reasons for what you think you're going to do. We also do it alone. If I'm imagining I want to buy something on Amazon or I want to take a trip somewhere, you'll start rationalizing and justifying it to yourself. When you want a piece of cake, you will come up with a justification for getting the cake.