well.. here, I didn't mean it in the literal way of 'pushing them', you don't necessarily need to push them unless they really do need one (kidding, am not that mean).
what I meant was not to 'shun' away those people whom you feel are/were close to you.
As we grow old we often tend to stray away from those whom we were once close with, which many a times happens because of our changes in life,the distances or situation surrounding us. And those people can be our high school friends, our childhood pals or our once college besties.
With times I have realized that, there are some people who no longer keeps the same bond which they once had when they were close, maybe it is our busy life which is to be blamed for or say the gaps between! and, it is indeed sad to think that you can no longer share the same secrets to your close buddy with whom you always did when you were friends.
If only we had spared a little time to wish them on all their birthdays instead of missing it or forgetting the dates though they are not near or if only, you had sent them a daily 'have a good day' message, maybe things would have not turned this bad, where now you are no longer in talking terms.
However, you are not to be blamed either, for people who wish to stay in your life will do it, no matter what and if they wish to keep in touch with you, they would surely make an effort to do so, instead of just waiting for you to take the first step.
Or maybe you should have told them how much you mean to them, and if despite reminding them about it and they tend to not bother than its okay to let them go. Who knows? maybe they were meant to be with you only for a short span of time and not till the end.
At least you aren't the one pushing them away, they choose to be away! you need not be sad or regret but accept it with a happy face.
For am sure they were just a part of your life story and weren't meant to be there for you till forever, for as it is said, 'we meet and come across people and the one who stays with you till the end are the ones worth to be treasured' so, treasure the one who are now there for you... and yeah don't push this one away, keep them really close!!