Robb, I had no problem with laughing but about 4 weeks post op my chest became hypersensitive. As I've mentioned elsewhere, my cotton T-shirts could periodically feel like sharkskin and those new chest hairs growing back out could feel like barbed wire. This usually has nothing to do with the chest itself but is the brains way of reprogramming itself to deal with the healing nerves. For awhile the brain can periodically interpret all sensation from the area around the incision as pain stimuli. Mine wasn't constantly extremely painful - that came and went - but it was very sensitive for about 6 weeks. My Cardiac Rehab nurse had me start doing sensitization routines which involved rubbing the area with items of different texture several times a day. I used soft cotton, silk, a pumice stone, a wash cloth, etc. After about two weeks of this, the sensations began to fade until things had returned to normal. Once in awhile, I still have some of these sensations return for an hour or so but then it passes.
Like Lilly, I also developed costochondritis which is an inflammation of the cartilage between the ribs and the sternum. When this was most troublesome, the hypersensitive became a problem again at times but it faded as the swelling went down. Basically, these are just after shocks and hopefully will all recede permanently.....someday.
Larry