Habits which Lead to Forgetfulness

The Talmud mentions a number of habits which can lead to forgetfulness in Torah study. They are:

Eating something which was nibbled by a cat or a mouse;  eating the heart of an animal;  being accustomed to olives (as opposed to olive oil);  drinking water that was left over from washing;  washing both feet together;  using clothes as a pillow. (Horayot 13b)

Other habits mentioned by our Sages as causing this problem include wearing two garments at once (MB 2:2) and wiping hands on our garments. (Tashbetz Katan 287)

It seems that many of these habits have a common theme: they involve laziness and shortcuts. Instead of making the olives into oil, which in the time of the Talmud was the most accepted way of eating them, this individual takes a shortcut and customarily eats the olives plain. Instead of drawing new water for drinking, he uses the water left over from washing.

Instead of washing each foot separately and thoroughly, he takes a shortcut and does them both together. Instead of arranging a proper pillow and folding his clothes, he "kills two birds with one stone" and uses the clothes as a pillow. Instead of putting on each garment carefully and separately, he takes a shortcut and puts them together; instead of taking the trouble to find a towel or rag he merely wipes his hands on his garment.

Many, perhaps most, of the traits which our tradition connects with forgetfulness in Torah study are symptoms of a penchant for time-saving shortcuts. A person excessively imbued with this trait will find it difficult to retain his Torah learning, which is acquired only the long way - through patient and diligent study and review.