they both had to laugh, because they know that unknown, the monsters, the running is the best part. No chance is either of them going to give that up. No way they're just going to ignore whatever is going on here.
"The path I carved through time and space, from Gallifrey to Trenzalore. My own personal time tunnel, leading back to every moment I ever lived. Every step, every tear, every kiss. Even the days I haven't lived yet. Which is why I shouldn't be here. The paradoxes... very bad..."