Appreciating the small big things (or is that the big small things?)

Riley has resisted tummy time for a long while. He's just been happy sitting up, chewing on all and sundry. Yet I persist to put him on stomach, to exercise his muscles, get him used to it. Then tonight, out of the blue, he tucks up his knees underneath him, lifts his butt--and goes backwards. He's kind of scuffled back before, but I think it was pure accident. This time, it was a coordinated effort. And, perhaps before I know it, he'll be going forwards! Times like this, when I get all giggly and whirly with motherly excitement, make me realise that for all the bitching I do about the bad stuff-- the good stuff comes and goes so quickly. Pretty soon he won't be a baby anymore and for some strange reason tonight that is making me all teary!