 Also, it's hard to maintain enthusiasm for 21 days. There's just so much time you can spend staring at a view. I mean, how long is one supposed to look at the Eiffel Tower for? It's not like it does anything. A place has a way of pushing you out when it's time to leave. A favorite restaurant you return to for your final night is suddenly limp and uneventful. A last drink with a friend, more perfunctory than celebratory.