A trick for bringing sandwiches to work:
Normally, if you buy a loaf of bread at the beginning of the week, peel off two pieces each day to make a sandwich, and otherwise just leave it sitting out, it’ll get moldy by the end of the week, wasting a good part of the loaf. Putting it in the fridge will just dry it out. So instead, soon after buying the loaf, stick the entire thing in the freezer. When it comes time to make the sandwhich in the morning, break off two slices, and make it as if they were just normal pieces of bread.
By the time lunch rolls around, voila! non-moldy sandwiches.