Here's a pretty reliable jam session rule: Get four or more people together to hang out, one with an acoustic guitar, and before two hours pass, someone will start playing Oasis's "Wonderwall." It works even better if those people are British, better still if they're British musicians, and even better than that if they're British musicians constantly described as the faces of the new British Invasion. Of course, at that point you're basically just describing One Direction, but still--the rule works. Of course they covered Oasis on the beach (and possibly on the set of "What Makes You Beautiful.") Of course Niall took guitar duties, and of course Harry took a break to goof off. That's just how it works.
A question, though: How did nobody inform the Olympics about this? Emeli Sande got two songs. Jessie J got at least three. Elbow got one long multi-part dirge. Surely there would've been a way to let One Direction do "Wonderwall" instead of giving it to Liam Gallagher by his near-lonesome. One invasion makes way for another. That'd have been patriotic, right?