His knees must be too sore

So, today is the first day Bostyn has just been walking around ALL DAY. I haven't seen him on his knees. For weeks he's walked across rooms, to mom and dad, or to something if it was close by. Well, his knees must be sore because today he's been roaming around everywhere on his feet. (I have noticed his knees have been permanently dirty and rough from using them outside so much lately)
It kinda makes me sad to realize he's already 1 and walking around. My memories of his birth and cuddling him as a new born are so clear and nearby. How could it have been last year????