Answer:
It basically means that if one is taught halfheartedly, one will remember it for a certain time but if one is taught with full interest , and the teacher is able to capture the person's complete attention, one will remember it for a life time andalso means that if knowledge is provided, not with full intention of gaining the maximum from it , it won't be of much use. If something is taught to you with full guidance and compassion , it'll certainly be a life time achievement.
The interpretation above is BS. A much more literal interpretation would be that if you fix a symptom of a problem, it is only a temporary fix. If you fix the problem, the symtom will go away. This can be applied to anything. I try to use the principle when people ask computer questions. You can give them the answer and they will be satisfied until they have another question or you can teach them how to find the answer themselves and they will be self sufficient.
Taken literally, the proverb means - don't just feed someone a meal, teach them how to provide for themselves.