On the matter of children leaving home, most likely this is something that parents cannot change. But that does not mean parents can do nothing about it. Parents can either move closer to the children and change themselves to adapt to their children’s needs or try to be a more understanding parents to their adult children, so that they can form a good relationship with their children.
In fact, our relationship with the children has to evolve as the children grow up and the parents age. From what I can see the relationship with the children is very crucial to our happiness.
The comfort for the parents is they might sever the tie with their past, their childhood, their high school friends, etc. but their ties to their parents will survive everything.