Khan was i thought sitting on top of his plant when i went in to change his water he didnt move then all of a sudden struck . . . think he must have been sleeping and i woke him.
Shell, that does seem to be the case given your description.
If you think a snake may be asleep but you need to do work in the viv without startling them it is a good idea to just give the viv wall a gentle tap, the snake should feel the vibrations and wake up rather than striking when you put your hand in. This is especially good for larger snakes that you really do not want to take a bite from... just remember not to thump on the walls or you may end up getting tagged anyway!