Trying to rejoin reality after an extended stay in Venice can be dangerous. You forget about looking out for cars and get used to just walking in any random direction knowing that, since you’re on an island, you’ll eventually get where you’re going. Avoid the post-Venice “bends” by decompressing in Florence, which has lots of pedestrian-only areas in its compact core of sights and a giant freaking cathedral dome you can use to orient yourself from just about anywhere.