It is very important that those involved with adoption not let their children become their only or even primary purpose in life, especially after those children are out of their house. Clearly you will have a lot of focused time with them when you raise them, but learn to let go once they are adults.
I know this is a general
principle for raising children in general, but it is especially
important if/when those children decide you are not really a valid part
of their lives. This can happen with children who are born in a family,
but those children don't have a valid alternate family to run to, while
the ones we adopt do in many cases.
This makes it all
the more important that you find a purpose that doesn't require them to
be an ongoing active part in your life when they are adults. It may be
great if they do maintain contact and a connection, but making sure you
do not rely on that is required if you want to stay sane.