Ive been stressing over very small things alot & now i have been lost for hours.... I use Maya to model & animate. I create a ball,

My Problem in detail:

1. I set keyframe 1 with ball in position A.
2. I go to keyframe 8 and set ball in position B located above position A.
3. I click Play Ball moves from position A to Position B without any problems. Now this is where I get mad.
4. After many hours of learning to model, I model a character.
5. I create all the joints, Bind them to skin of character, clean it up with weight painting tool. THEN
6. I set joints and character model in keyframe 1 in position A.
7. I go to keyframe 8 & rotate characters arm joint into position B
8. I Press play and.... NOTHING HAPPENS!

Character stays in Position B It has not saved its keyframe 1 position, I simply cannot animate the joints. Now i was working on many different details in animation creating his idol stance which involves the chest breathing and alot more spent 10 minutes or more doing this and it didn't animate.

Please somebody answer the answer is not on google its nowhere and im sure somebody here has experience with animating the characters joints.