A week or so ago, D2 rolled over (front to back) several times in succession. He did it again the next day. Since then, nothing. It irritates him now even to be put on his tummy, because, hard as he tries, he can't seem to repeat the activity.
His sister has already gone through this several times, with each new skill she has mastered. First there is the grandeur of that first successful movement–clumsy yet oddly graceful, as if one were watching a human being fly for the first time. It seems like a miracle that they can move at all.
Then frustration sets in. Much as we–and they–would like to think so, doing something once doesn't mean you can do it on command every time thereafter. They seem extra fussy in general at this time. Suddenly their sights have been raised and they want more out of life: to roll over instead of lying still, to crawl instead of roll, to walk instead of crawl. But the muscles haven't yet learned to make it automatic yet. Sometimes the skill lies dormant for weeks before they can even repeat it.
Yet something finally does click, and they can at last do it whenever they want. Soon it becomes commonplace to see them moving in the way that seemed impossible a month ago. Being children, they're soon on to tackling the next challenge.
Meanwhile, it's hard to watch them struggle. Mostly it seems to be my job not to interfere too much, and to ease off on any other pressures while they consolidate their new skill. At D2's stage, where I still have some control, I try to put him down on his tummy fairly often, but not leave him there until he can't handle it anymore. Later on, it's more a matter of stepping back and not interfering while they learn their own limits.
Before too long, learning to crawl and walk will be replaced with learning to read and add. I need to remember how learning happens–that sometimes a new skill needs a rest, that it may frustrate them as much as me that it doesn't all come together at once, and that someday it really will click, and that oh-so-difficult skill will be second nature.