We know the proverb, “Birds of a feather flock together.” People who have similar character or interest tend to enjoy spending time together. Research shows that friends tend to share the same brain waves and react to situations in the same way. It further states that we change our friends with our evolving beliefs and interests. The most important of all is sharing enthusiasm with matching brain frequency is very important for solid friendship. Is this an essential criterion?

Yes, it is. Our ancient literature says even if we spend most of our days with someone but could not mentally connect with them for a few days, you should not make them as your friend. Likewise, a friend with whom you are not in touch for a long time should not be a reason to be abandoned. So it clearly says you should make friends with similarly interested people and once you make such friends, we must keep that friendship strong.