In spite of wanting to see his friend, the  wise man restrained himself, thus not visiting his friend for many days.

When he did go to visit him, his friend remonstrated, 'Why have you taken so long to visit?'

The wise man replied, 'It is better than you asking me, why have you come again?'

Friendships are strained and even lost by interacting either too rarely or too often.

Friendship is like a 'Diya', an oil lamp. It requires a regular supply of fuel oil to keep  the flame of friendship alive. 

Meeting rarely or staying out of touch for long periods, is like depriving the lamp of sufficient oil. As a result the flame flickers and eventually dies out. 

Meeting too often is like pouring an excess of oil into the lamp, thus extinguishing the flame. Only the empty lamp remains, possibly with a few sparks but there is no flame. So it is with friendship.

Another way of understanding why friendships do not sustain is, what I describe as threshold capacity of one's personal space.

Each person has his or her threshold of having other people in their physical, intellectual, and emotional space.

Some need and want more, others a lot less.

Spending a lot of time sharing space with others, like in the army, or in travelling or working intimately together, being a member of a large and active joint family,  or having spent an extended time at boarding schools etc. it tends to enhance the threshold of accepting people in our life space.

Hence, I have a very high threshold for accommodating a large number of high intensity interactions simultaneously.   On the other hand my wife Mohini and some of my friends have a low threshold. They need the comfort of their private space a lot more and calibrate their lives accordingly.  

When friends, even good ones with widely different thresholds share their personal space, then, either sparks fly or exhaustion causes them to withdraw.

The solution is to be sensitive and understand the threshold levels of others. 

Unfortunately people sometimes misjudge or forget where that threshold level is, and I am one of them.

Note: Understanding and respecting the threshold is applicable not only to friendships but in fact all relationships. It is key to achieving success and realising happiness.