A simple thank you

OK... I am a very helpful person... and all I ask in return is a simple thank you.. thanks... something...
Why is that so hard for people to say... even if its part of my job... if its something that is expected of me... why can't people still say thank you...
My ex. used to think it was stupid to tell me thank you. And it irritated me to no end.. I would like to know once in a while that I am appreciated...
I would cook dinner... not a thank you... I would do laundry... not a thank you... I would clean the house... not a thank you... And heaven forbid I tell him Thank you for something that he did that "is expected" well that was just the start of an argument... he would tell me that Im stupid. I don't need to patronize him by saying thank you... I wasnt trying to.. I just wanted him to know that I appreciated all that he does. Why is it so hard to accept and to say for some people!!!!
I know with work and everything its a little different.. its your job but still... why can't someone tell you thank you for something that you do... especially if its over and beyond your job description and you are helping them out!!

THANK YOU FOR TAKING A MOMENT OUT OF YOUR BUSY DAY TO READ MY BLOG! :-)