I tried to book a flight to a remote island, but they said it was fully booked.

This joke serves up a delightful slice of wordplay, hinging entirely on the clever confusion between two words that sound alike but mean very different things: "desert" and "dessert." The setup about a remote island initially conjures images of an exotic, perhaps even deserted, locale. But the punchline masterfully pivots, playing on the common phrase "no room for dessert," which usually means you're too full for a sweet treat after a meal. Here, it's humorously applied to the availability of a flight, suggesting there's no space even for a dry, barren land.

The humor mechanism is a classic pun, where the similar sounds of "desert" (the sandy landscape) and "dessert" (the after-dinner treat) create an unexpected and silly twist. Remote islands have long been subjects of fascination, from tales of castaways to idyllic vacation spots, making the idea of booking a flight to one a relatable concept. The joke takes this everyday travel scenario and injects a spoonful of linguistic mischief, leaving you with a groan and a chuckle as you unravel the delicious double meaning.