bedtime

Noah, my 2yrold, used to be sooo good when it came to bedtime. Brush teeth, give kisses, hop into bed for a story, lights out, and we wouldnt hear from him until the next morning. but this last week. everytime we put him to bed (my husband andi usually switch, one night ill put him down, the nextnight he will) it HAS to be me. Noah will scream and scream 'mama' until i come. and even after we put himin his bed andread him a story, he gets right back upand REFUSES to stay in bed. and again, will scream and scream and scream. for the most part we're prettyfirm with him in staying in his bed,butsometimes, if i realize he really isnt tired, ill let him stay up with me for a bit longer.
last night after i put him to bed, after a lot, a LOTof fussing, finally, i just closed thedoor (not fully, because the doors inmy home make a lot ofnoise when you open them, and i like topeek on him before i go tobed) anywaysand ijust lethim fuss and cry. well,like 30min later he was quiet, so i wnet to check onhim, and he grabbedhis blanket and pillow and stuffy and was lying on the floor by thedoor.
so anyways, i guess waht im getting at is, i dont understand what the sudden change in him is all about. why now, after so long ofhim going to bed happy, is he being so fussy and stubborn. andhow do i deal with this???