For Europe, I usually take the evening flight from SFO that arrives in the afternoon, often to London, for a few days. If I get a couple of hours of light sleep, I am grateful. I make a point of getting to the hotel to drop off bags, have a snack. (Scones and tea if in London), then head out for a walk, a park or natural space included, if possible. Then a light early dinner, relax a bit and sleep.
I wake up early the first few days but not too bad and am mostly good to go. Agree the excitement is probably part of the reason.
Returning is another story. Several days of being pretty spacy and more of feeling very tired. Is it jet lag or am I just very tired from travel? My wife and I are walkers and often average 8-10 miles and sometime more on our usually 4–7-week trips. We try and cut back but we just can't help ourselves as we find walking around very interesting and often find unexpected adventures.