Because he’ll be going on about stars and stuff and everyone will be like, “I didn’t know he knew a physicist! How did he know a physicist?” and they’ll be whispering to one another, “Do you know who the physicist is?” and nobody will know who he is and it’ll be pretty mysterious because this random physicist is at your funeral talking about stars and conservation of energy and stuff.
And then people will maybe suspect that the physicist is someone you knew through work, but how would you know a physicist through work, you were an account manager for a mid-size estate agency specialising in warehouses.
And then people will be like, was the physicist a friend of his wife or something, and your wife will be like, “I’ve no idea who this physicist is, I thought you guys knew him” and everyone else will be like, “No, we’ve never met the guy” and your wife will be like “That’s weird, I’m sure he would have told me if he was friends with a physicist, I don’t remember seeing this guy on his Facebook page when I spent several weeks hacking into it when I thought he was having an affair with Claire” and Claire will be like, “You thought what?” and your wife will be like, “I’ll tell you later.”
And you’ll want the physicist to say the word “quark” because it’s a nice word and it sounds like something a posh duck would say.
And then when the physicist has stopped talking about quarks and Brownian motion and how it relates to your dead body and everyone is going “Who are you, anyway, and why are you talking at our friend’s funeral” you want him to shout “PHYSICS AWAY!!” and run out of the church like a super hero.
Also, you may want a physician to talk to you about cholesterol before you die.