I just finished reading Jojo Moyes's "Me Before You" which is probably the most depressing book I've read in recent memory. I finished it on a Friday night and it haunted me all weekend. I'd forget about it for a minute and then I'd remember again and my chest would tighten and tears prick my eyes all over again.
One line that really got me was uttered by the mother of a grown man, whose life did not turn out as expected or hoped. I no longer have the book (it disappeared back into the cloud when my library checkout ended), so I can't quote directly. The gist: When you look at your grown son, you don't see him solely as the man he is right now. You smell his sweet baby smell, feel his sticky toddler hand, hear his schoolboy jokes, and his rebellious teen years. It all blends together and you see all of it at once.
I'd counter that you don't have to wait for your children to be fully grown to witness this phenomenon. And I'd add that in addition to the past and the present, you also see the future selves of your children.
B still has tantrums that remind me all too vividly of him at 2-3 years old. He still plays with the tub animals and chews on his blankie, and has trouble using a fork. There is a lot of baby and toddler still there. But he also runs off with his friends without a backwards glance at birthday parties, and asks questions about planets and how the body works. He helps his brother learn how to share, and do puzzles, and get dressed. I see the smart, sensitive kid he's becoming.
L still needs frequent snuggles and sucks his thumb constantly. He needs his teeth brushed and his clothes changed and isn't 100% with the potty-training. He is still in frequent tantrum-mode (he's 3 after all). Definitely a lot of baby there. He also makes up funny dances and songs, and cracks us all up with his antics. I see the clever, light-hearted kid he's becoming, too.
I reminisce about the past, revel in the present, and very very much look forward to the future.