I tried to book a flight to a remote island, but the travel agent said it was impossible.

This joke soars on the wings of some delightful wordplay, specifically a pun. The punchline, "I guess I'll just have to wing it," hinges on two distinct meanings of the phrase. Most commonly, "to wing it" is a familiar idiom that means to improvise, to do something without prior planning or preparation. It's the go-to phrase when you're facing an unexpected challenge and have to make things up as you go along.

However, in the context of trying to book a flight, the word "wing" immediately brings to mind the literal wings of an airplane, which are, of course, absolutely essential for flying. The humor arises from the impossible situation of being unable to book a flight to a remote island. When conventional travel is off the table, the speaker suggests improvising, but the choice of words subtly links that improvisation back to the very act of flying itself.

It's a clever linguistic twist that connects the abstract idea of spontaneous action with the concrete reality of air travel. The joke playfully acknowledges that sometimes, even when plans are grounded, a bit of creative thinking – or creative phrasing – can still get you moving, at least in spirit.