what is half a brother?

Josh takes his time in considering everything. He has more going on in his mind than I can even imagine.... and some days out of nowhere, he mentions something that he has been bouncing around.... and when it is the first time he brings something up it kind of surprises me. Not to mention, his time and place can sometimes leave alot to be desired... it just comes out when he is curious or ready!
The other night the boys and I were coming home from hockey, on the bus, Colin was asleep, Aidan was playing with Colin's stroller toy and
Josh pipes up "These two are real brothers and I am a half brother"
Okay, he got my attention! Is true but needed some tweaking.
Me..."What is the difference?"
Josh..."They share both of their parents and I do not."
Me..."And... that's not news Josh, why are you thinkin about that?"
Josh..."No reason, just that I am only half a brother."
Me..."Not in my opinion! Why does that bother you?"
Josh..."No, not really."
Me..."A real brother is someone who you grow up with and share your life with and fight with and be best friends with, you all grew inside of me and YOU are their whole and real brother in my thoughts! I do not want you to think you are not!"
Josh..."Hmmmmm,"
Me..."That is what really counts Josh, believe me, they would tell you the same thing, and maybe they will someday!"
Josh..."Yeah"
Me..."You having a different Dad, has given you 2 sisters, they do not have that!!"
Josh..."Yep! That is true"
Me..."You are special, like always!"
Josh..."Special?" with his goofy face
Me..."Ya, not the *retarded kind just plain special"
(*that off comment was playing down to the 13 year old mindset and does not represent the views of this writer, hehee)
What a kid! Watching Brothers and Sisters later that night did the same topic not come up in the show! We chatted again and he hopefully understands that he is a full on 100% brother to the brats he would try to sell on ebay if he probably could!