Homework struggles

Last year, 3 year old Robert would come home from preschool and announce he had homework to do.
     ROBERT:  Mommy, I can't play with you right now.  I have homework to do.
     ME:  Really?  What kind of homework do you have?
     ROBERT:  Email.  I have to check my email.
     ME:  Oh, OK.  What is email?
     ROBERT: I don't know.  But I have to check it!

So, we had that conversation a lot last year, even though he never had homework.  I think he got the idea after being told from his older friends in the neighborhood that they couldn't play right after school because of homework.

Fast forward to last week.  Robert has been given his very first homework assignment.  Yay! I was excited and assumed Robert would be, too.  He has to sign his name on fifteen homemade Valentines Day cards.  So far I have gotten him to sign just three.  He is full of excuses:

"Mommy, my legs are tired"
"I'm sleepy"
"My hand is too tired"
"I need to play the Wii to get ready for my homework"
"Is it Sunday?  Because I can only sign these on Sundays"

I've tried bribing (and that's how I got the three signed), I've tried timeouts in his room.  We bought Spongebob stickers yesterday at Giant, so I'm hoping that will do the trick.  Something tells me that on the morning of Feb 14th, I'll be signing these cards with my left hand, trying to forge a  4 year old's signature.

I thought I wouldn't be having these homework fights until Robert was a teenager.