It's a matter of principle.

Merging in traffic is like an upsidedown zipper.

Do I need to explain it? It's really freaking simple people. Every other car merges into a nice, pretty little line. And when that starts to happen, you're not supposed to be an Ass and floor the throttle just so the people in the right lane have to hit their brakes.

Naturally, I didn't let the said Ass pass me on the left.

It's a matter of principle.