For Charlie, the 15-24 month stage. He was sleeping well (so took it for granted!), he was well-behaved, and it was so much fun watching him learn new words. There was just an explosion in learning, but he was still my sweet, little boy (before the tantrums started).
For Olive, I miss the first 2 months when she was a sleepy newborn and I could take her anywhere. She was so cute and sweet!!
What about you?