Elliot started crawling so quickly at 7 months (seriously, like a couple days of practice and then he was off! haven't seen him since!) that he never really took the time to master the art of sitting unassisted. Who has time to sit when you can CRAWL?! Places to go, things to do. Within the last few days, I've actually wondered if he COULD in fact sit without any help, because I'd never actually seen him do it.
All of a sudden, he was like, oh cool, here's something else I can do while I'm down here if I don't feel like going anywhere but don't want to lay down. And he sat there on the carpet chewing on a [closed] marker for like 15 minutes. So, um, ok...guess that answers that!
Should I also mention that just a week or two after he started crawling, he discovered the art of pulling up (and letting go)(and falling over)?