Im also leery of having a key for a lock with me on a trip, but thats just me.
Not just you, I feel the same way. And when I put my cable lock away, I don't lock it since on one tour I completely forgot the combo. Took an hour to try the various combination I could remember. It turned out it was the last one I tried, as always ;-) So now I leave it unlocked so when I take it out to use it, I can look inside the lock and see the tumblers if I forget the combination. That way hopefully I'll remember it for the short time I'm in the store/cafe after I lock up.