Those rounds include everything other than golf on your mind - work, family, etc. You will often times find yourself going through the motions on the course just to get done, especially late in the round. Generally your score will reflect the lack of effort.
Golf is a four-hour test and requires the ability to concentrate over every shot.
The shortest of putts can be missed and the easiest chip shots can be muffed if you're not focused. Grinding from the first tee through the 18th green becomes extremely exhausting. The key to success is to allow your mind to wander in between playing shots, but focus on the task at hand when over the shot. The next time you find yourself going through the motions, find your own way to get your game back on track. You'll be surprised how mental the game really is.