This used to happen to me every 2 weeks or so  the first 2 years I owned my Wii. Then, when I moved, it rarely happened. I hated re-syncing. D: Now, I don't really have to do it.

What game were you trying to play? Something similar happened to me recently, and I think I know what's doing it. The reason why? No idea. Like Arnold and seth, I've had my Wii since launch and every time I went to launch the new Sin and Punishment game, the controller just wouldn't assign to player one. Tried re-syncing, no luck, so I just closed the Wii and tried again and it worked for some random reason.

And then I was trying to play two player with my bro and the second controller just would assign to player two UNTIL we press the Two Player option in the game. Really weird... o_O

In my 3.5 years I have owned a Wii, this has never happened to me

never happened to me...

I've had this prolem with all of the consoles.  With the PS3 and the 360, I end up connecting them to the console via the USB port (I honestly still don't know how to sync those two consoles).  With the Wii, I have to play by the rules and push the red button.

Neither happened to me, i think that this may be too much wireless interference like routers or bluethooh diveces too near from your wii console.

Usually, pushing red buttons leads to things self destructing.  What if you pushed the wrong red button and blew up your galactic space ship Zapp?

Buttons is made for pushing.

This occured at some point to one of my friends. We tried and tried to sort the problem out, it was near impossible. After several days we sorted it out, it was not to do with the synchronization but was to do with the batteries, due to a problem with the recharger. Are they rechargeable batteries? 

nope not rechargable but i got it sorted out, i resynced it, its probably caused by either my PS3 or Cell phone , because of the bluetooth , it didn't happen before but its no more, for now i still have the updating issue though, should wait for the servers to go back.