Originally Posted by
Restingvoice
It's an extension of Tim not having enough sleep during his Robin run. Staying up all night working on cases, falling asleep during a date on a rollercoaster, falling asleep on a coffee date, falling asleep sitting down listening to music in his bedroom floor, falling asleep on a rooftop while taking a bit of rest... there's only like one panel of him ordering whatever as long as there's caffeine in it, but since the idea is he likes to stay up late, fandom just adds coffee
So the coffee is the reason he can stay up late
Bruce burning down the kitchen is from Tim's era. One time Alfred quit, so Bruce has to take care of himself, and he screwed up a tuna sandwich and add too much detergent to the laundry machine. The other time is in TNBA comic adaptation, he actually burned down the sandwich/waffle he meant to serve Alfred and the kids as an appreciation to them.
Jason coming only for food I think is an extension of him breaking into Wayne Manor during Batman Eternal. He and Bruce were not in good term, but he asked his help to watch Barbara, and he came breaking in, with Bruce referencing that there are other times he broke in and he had to replace half his security measures.
There are other times too, I forgot which Outlaws, when Bruce was away, Jason snuck in to get his leftover belongings, but caught by Alfred.
This led to the joke that, since fanfic are lighter, that Jason breaks in EVERY TIME, even after he's given the keys to the Manor and in good relationship with them. (of course this also goes into him breaking into Batman's safe houses to steal supplies)
Of course, Tired Dad Bruce is just the natural result of all of those. How can he not be tired with all of those happening at the same time.
It's also comes from fandom with large family that doesn't believe that Bruce isn't tired living with all these chaotic kids (of course the real answer is because only 2 of them stays in the Manor at a time, but we ignore that because that's not funny)