Becoming Mobile

I've spent the last 2 months watching Jackson learn to crawl. I had expected him to first learn to push up on his hands and knees, then rock back and forth, then start to take crawling steps. I didn't expect it to be such a journey.
He's always had good head control and ability to push up. For the first 4 months, Jackson was able to push up on his hands higher and higher. Around 4 months, he started to push up onto his hands and knees. He would keep pushing on his arms, which caused him to slide backward. Since he was interesting in reaching something in front of him, this resulted in anger and grunting and grumbling, sometimes yelling in frustration. Around this time, he also learned to pull up on the sides of his crib--something I was not ready to see happen yet.
Since the hands and knees thing wasn't propelling Jackson forward, he went for a change. He started pushing with his toes. Since his hands weren't moving, he would push up on his hands and feet, into a little yoga downward facing dog. He spent a lot of time in the downward facing dog. From there, he would tip his bum down and to the side, making a 1/4 turn into a sitting position. Once seated, he then either sits and plays, or gets into another downward facing dog and makes another turn.
I wondered for a while whether he would crawl on his hands and knees, or his hands and feet.
The downward facing dogs became more and more frequent. Jackson wakes in the night and sometimes turns downward facing dog pirouettes until he settles back into bed. Sometimes he starts right into the pirouettes instead of going to sleep.
At 6 months, Jackson took his first crawling hand steps. He would take one or two handsteps, then fall down on his belly, rest, and get back up for a couple more. Using this method, Jackson could travel 5 or 6 feet. This was an intense and laborious process. He usually incorporates a few downward facing dog pirouettes just to mix it up. Once he reaches his goal destination, he pirouettes into a seated position and then huffs and puffs like an exhausted runner.
Monday, I left Jackson playing in his room and walked around the corner to do some laundry. After a few minutes, he crawled out of the room, turned the corner, and sat down in front of the dryer to watch me.
Today, he's crawing pretty well. He can travel across the room and sit down. There's little huffing or puffing.