My dd5, skipped K to grade 1, cries pretty much everyday at school - either because she worries she's done the wrong thing or that she has missed something important or because she can't decide whether she wants to play with her friends or on the play equipment (looking for the best choice...sigh) and then misses out on doing both. She cries when there is something she find scary in a class video... I could go on. I am very fortunate that the teacher has recognised this as sensitivity rather than immaturity and has some work arounds in place (another trusted kid to give her a hug, etc) - or just expects her to get on with it in some cases, which I think is equally valid at certain times.
At home we're working on realising that every moment can't be perfect and her behaviour can't always be perfect (currently she says she feels guilty whenever she overreacts - so now we're focussing on understanding she shouldn't feel ashamed of her behaviour and look at some other choices she could make in the future). DD is also very conscious of wanting events to work out 'just so' and making sure she follows 'the rules'. So we're having lots of conversation about having to make the best of the moment as it is, otherwise life is going to be pretty disappointing (so few perfect moments). My goodness... sometimes I'm spent by 8am and we haven't even got out the door... sorry I went off on my own tangent.
I know it's been touted on this board a bit recently, but the Living with Intensity book is great and worth a read, even just to get an idea of where their thinking can be at.
