A Book

Experience:

There is this book that I read about 10%  when some events interrupted and the reading was terminated.  I pick up this book today and found myself don't remember much! 

Conclusion: 

A book reading process must be carried out regularly and frequently for the brain to weave a really strong web of it or the memory will decrease (exponentially?) with time. A few pages a day or a week is not a bad solution as the brain can always recall something that happened last week which have some connection with something that happened longer ago.