Friendship, like many other things in life, can have an expiration date. There are some friends who stay with you for your whole life but there are also many friends who come into your life and are part of it only for a certain amount of time.
Through our lives, we grow and change. Ideally, our friends will grow and change with us. As we mature, we develop different attitudes and different needs.
Some things that we considered necessities in the past become things we can do without in the present; some behaviours, political views or religious affiliations that we could accept before become deal breakers, today.
We realize that some people act in ways which didn't bother us so much when we were younger, but now these behaviors have become intolerable.
As we grow stronger, healthier and more conscious, we begin to see all of our relationships much more clearly. We identify the friends whose values we once shared but who we see today as just too different from us.
Sometimes we simply grow apart as we make life choices which put us in different social or economic circles. Some people choose a more traditional lifestyle while others opt for a bohemian way of life.
If we're middle-class and our friend has become wealthy through inheritance, career or marriage, it might complicate our relationship unless both of us are able to handle this potentially tricky situation.
We can also get into conflicts or misunderstandings with an old friend. As we evolve and change, they might still be attached to seeing us a certain way. If they're unable to accept the new, more improved version of us, the friendship can't be sustained.
I've heard of a few instances where one person got married and their friend began acting funny around them. People get used to a particular dynamic and can be resistant to seeing it change.
If we've always been available at the drop of a hat and now have responsibilities and commitments associated with being a spouse, our friend may not be willing to accept this.
If our friend can't get over the fact that we're no longer at their beck and call, or if they become jealous of the affection we're giving our spouse, it may mean the end of the friendship.
Then there are the so-called "frenemies." These are people who we thought were our friends when we were younger and less aware.
We were invested in being kind and understanding, so we made excuses for their bad behavior and put up with their unreasonableness.
As we grew older and wiser we were able to see that their jealousy, competitiveness, complaining and attempts at exploitation became tiresome.
Their demands for attention, frequent crises and most especially, their betrayals could no longer be explained away. Our growing consciousness made it clear to us that this person had to go.
So, whether it's because you've grown apart because you no longer share the same values or lifestyle, or because you realize that the friendship isn't giving you what you need ( and maybe never did), it's time to un-friend this person.
Ending a friendship can be done simply by not responding to phone calls, texts or emails and gently letting the person get the point, or it may require a 'breakup' conversation.
Sometimes the former is preferable, especially if the other person is likely to become very hurt or angry by such a conversation.
It's upsetting and embarrassing to be rejected, so if we do have the talk, we owe it to the person to be as kind as possible. On the other hand, we also owe it to ourselves not to get into a major conflict over a relationship that we no longer want.
If the person won't take a gentle hint, or if the breakup conversation results in their becoming demanding or aggressive or if they try to make us feel guilty, we can feel justified in cutting off the conversation with no further explanation.
Many of us are sentimental about our friendships and want to believe that they should all last a lifetime. We need to be realistic about the true nature of friendship.
While some friendships will be sustained for many years, even forever, many people in our lives will be there only for a certain period of time, and this is perfectly natural and acceptable.
Follow Marcia Sirota on Twitter: www.twitter.com/rcinstitute