Not only is he known for being hilarious, but Jimmy Fallon is also for being more of the most cheery, and generous celebrities around. He just looks like someone you'd want to grab a beer with, isn't he? And maybe a big plate of fish and chips too, he seems like he wouldn't judge!
And hey, after he picks up the tab for the both of you (he is the rich celebrity after all), he'll probably leave a generous tip, because that's just the kind of guy he is!