i guess theres a survival issue with being a comedian. No one wants to die on stage so therefore they probably go to sleep thinking about how they would counter heckling. Im sure we’ve all done it when you have an argument with someone and then you cant stop thinking about how you could have responded better to get your point across. Got heckled at some gig once where some guy was shouting “you’re gay” at me (probably there for the very metal bands and we were’nt hard enough for him or something) anyway after a couple of times ignoring them i finally responded “In your dreams” which got a good laugh from the crowd and we carried on without the heckles. Was quite proud of that one 🙂