causing road rage

yeah I did I was so not paying attention and cut someone off on the interstate got a typical response a horn honk and a gesture with his finger. ok fine I deserved as much it was a bonehead move on my part, but how do you convey sorry my bad? waving seems a bit odd & I don't know that he would have seen my shrug my shoulders so I just went about my business. In order to make his point he had to get on my right side and flash me another bird as he drove by...whatever dude yes I was wrong, I got you're mad at me take a deep breath let it go. No no as he was about to exit off he had to roll down his window and flash me the bird one last time, at that point I started laughing which was kinda nice I needed a good laugh for a change.