In the moment - the oatmeal moments (and I hear you - #2 once cried for 40 minutes at 18 months because I had to change her shirt and she wanted it to stay on....
sigh... where is that bottle you were passing around in the other thread!?!
I can't be of any help b/c now I'm just as confused as you are. Yesterday DS2 cried for 30 minutes hysterically until he fell asleep on the carpet against the wall b/c he didn't want his shoes on. I assumed it was just b/c he's 2. I'm not sure if there is a hard line that distinguishes "normal" age-related behavior from OE.
