To sleep is to forget not, which is why, I suppose, students never forget a thing in my lectures.
If you have ever studied at night before you go to bed, you have without realizing it tested the inhibition hypothesis.
Because there were few, if any, experiences for you before you awoke, your recall in the morning will be almost total.
On the other hand, if you study in the morning and then are exposed to the experiences of the day your memory loss over the next six hours will be significantly greater.
The factors of emotion and stress,of course, play important roles in learning and forgetting. Also, the interactions between Long-term memory and working memory is as complex as it is important.
Some of these issues are touched upon in the links we have provided along the way. For now, lets switch our focus to what can be done to improve memory.