Sirius needed this. He really, really needed this. Getting out of the castle, getting off the ground for a while, it would be bliss. Maybe he could get some distance from those almost-memories that kept crowding their way into his every thought. Maybe he could figure out what had been happening to him the last few days, what those black holes in his memories meant.
Mostly he just wanted to remember, and to forget. It was all so bloody confusing...
"You said it mate. I can't wait to get up there. Feels like ages since we've flown just for the Hell of it, eh?"