Kai has been learning how to crawl for a while now, and this video was taken when he was six months and four weeks old. Shortly after this video was taken, his crawling movements became even more coordinated. He is also able to get himself into a sitting position. And just this morning, I left him in his cot while I went back into my room to grab a jacket. Came back and saw that he's pulled himself to a standing position.
After I left him at my mother-in-law's place this morning, she called to warn me that he's able to pull himself to a standing position.
Some may remember that I was worried over what the paediatrician said when she saw how heavy he was: That heavy babies tend to develop slower in terms of motor skills? So nah nah nah nah boo boo...
Terence attributed it to swimming, and I think the fact that we made him do "exercises" even when he was just a newborn helped. (E.g. gently pull him up to sitting position, weight bearing etc.) These had both our moms screaming in protest of course.