Buddha dealing with pain If enlightened beings aren't bothered by pain, why did occasions happen where Buddha was unable to give a lecture because the pain was so severe or when he had to meditate to lessen the pain he was feeling.

Surely if the pain truly didn't bother him, he could have just continued as normal without needing to do anything special. 

Thanks.
Enlightened beings are not bothered by pain. But if you try to sit through severe back pain, it could lead to further complications. The body requires lying down to recover from back problems. So it's the sensible thing to do. When the Buddha is resting, he usually resides in the Jhanas. Even when the Buddha is not resting, it is said that he enters the Jhanas between every sentence he speaks.