Almost any rule that requires in game bookkeeping tends to be ignored (or forgotten): such as encumbrance, ammo, most spell components, etc. If the answer can not be resolved with a quick die role or yes/no answer, then it tends to fall into DM ruling on the fly to keep the story moving. Routine activities are all assumed to have occurred, such as eating during the day, maintaining appearance, dressing appropriately for the weather (and getting in out of the storm), adhering to character ideals (pray, practice professions, etc) etc.
Only when there is an unusual challenge, a plot requirement, or significant cost or repercussion do the bookkeeping/rules checking become part of the game play, but I have usually prepared for it ahead of time and the adventure provides plenty of clues that it will be an issue. Such as a known heavy box to deliver is expected to have an impact on encumbrance, even if the overly stuffed backpack the halfling wizard is carrying is winked at.
Between adventures, the bookkeeping falls back into play -- bills are paid, money is spent, etc. but time tends to be driven more by plot requirements than time values of administrative between adventure costs (which is why training time is generally ignored).
I tried several mechanism to better manage the bookkeeping in the game, mostly ammo, money and other resources. But it was still too easy to lose track as those resources shifted and shared so often. More than once has a potion been double drank during an adventure.
All in all, it works to the advantage of the players, but not to the detriment of the game or story. After all, they are the heroes.
