It is better to have loved and lost, then to have never loved at all. Shippou had heard it somewhere but he felt that his heart was too young to fully understand then.

Another thing the small kitsune didn't understand:

Was it better to have loved another mother, perhaps more than the first, and to have lost her then to have learned to grow on his own?

Perhaps, he decided, he should be happy to have known Kagome and leave it at that. Maybe, if Shippou had stayed with her he would have someday learned the meaning of it all...