"Parents can be delighted and enthused at the new things their kids can do and simultaneously feel the loss of their child's younger self." (Becoming the Parent You Want to Be, by Laura Davis and Janis Keyser)
The book quoted above is just right for me right now. In general, I bullishly resist most changes, and kids are changing all the time! I do look forward to their new accomplishments, and try to celebrate them. It's hard for me to welcome change. As they grow I see the baby self, that little boy self, leaving, slipping away. I let him go. I must, to love and support the new self as he grows. Always, it is the present child I must love, not the boy of yesterday. Yesterday's Gibbie or Ezra is a figment. Today's child is the one in front of me, the only one who asks for me now, and needs full engagement, the child who is.