What is my brother's problem?is he stupid?or trying to prove himself?

What is my brother's problem?is he stupid?or trying to prove himself?
My brother pissed me off a few months back
why would he tell me to move in when a picture is being taken of all of us ?

he was right next to me.I don't like anyone telling me anything and i just wanna go off on him.Am i blowing it out of proportion?It was other things before that as well...but when i told him he said he was sorry a few times...I told him not to tell me what to freeaking do,it happened a couple times before this...
I don't know if he is purposely trying to piss me off because he is older,but i am 180 lbs of muscle and he is 190 lbs of fat,and if he pisses me off he knows i can go off...what is he thinking?we are in our 30's for godsakes and its a friggin digital camera...He said my name and then said move in in a higher pitched voice.(it seemed like he was trying to irritae or piss me off)what the hell is his problem?then i went to the bathroom and he followed later and apoligized for something- i have no idea what...What gets me is that i told him RIGHt to his face not to tell me what to do about a few months before that and i even went off on him,and he said sorry .w3hat was his deal here...he WAS sick-he had some sort of stomach pain.but it still pisses me off...It's like he was trying to embarass me in front of family or something what is his deal?Doesn't he know i have a temper?