You should not behave in a seminar, the more you misbehave the smarter you look.
Our young star takes a nap usually. our nobel laureate, if he comes, he seems to either be fapping or adjusting his balls constantly.... These are smart people, so can you.
Sit in the front, and at important moments in the talk, turn back and pretend to make eye-contact with someone behind you. Then turn forward smiling and shake you head, fish out your phone and pretend to be unimpressed.
Leap to your feet and shout at the speaker; "any approach that claims to recover the distribution of individual utility parameters from aggregate data based on arbitrary distributional and functional form assumptions is dubious at best", then storm out.