Some relationships aren't meant to last. You're not likely going to have a lasting relationship with the contractor who built your home. Or the lawyer that represented you in some real estate transaction.
One of the reasons relationships wear out is that you can't have so many well-maintained relationships because there is not enough time to maintain them all. Some have to fall by the wayside, or you have to find a way to maintain them with much less frequent contact than when the relationships were fresh.
At the end of the day your longest-lasting relationships will be with the people nearest to you. Parents, siblings, spouses, children, close friends. All the others are at risk merely because you can't give them enough time (and they can't give you enough time). You can make some number of non-core relationships last, but you really have to choose to, and the choice has to be mutual.
One of the reasons relationships wear out is that you can't have so many well-maintained relationships because there is not enough time to maintain them all. Some have to fall by the wayside, or you have to find a way to maintain them with much less frequent contact than when the relationships were fresh.
At the end of the day your longest-lasting relationships will be with the people nearest to you. Parents, siblings, spouses, children, close friends. All the others are at risk merely because you can't give them enough time (and they can't give you enough time). You can make some number of non-core relationships last, but you really have to choose to, and the choice has to be mutual.