Lettuce, aka LeTUCE

My lettuce never really decided to grow.  I'm very sad.  I harvested a meager amount of lettuce...it should have been a whole lot more, but for some weird reason my seedlings never progressed much past that...seedlings.  I had a couple of plants flourish, but they weren't enough for a salad, so while waiting for the other lettuce plants to grow, they bolted.  Huh?

I got a soil test kit.  It says my pH and my fertilizers are "ideal."  Okay.  Then what could it be?  Did the cats pee on them?  Did something eat them from the roots? (I don't think so.) I'm stymied.  So I've decided to harvest my lettuce (pronounced le-TUCE in this house) and plant something else in those squares until fall rolls 'round and try again.  hmph.