It is to cerebrate.

To cerebrate means to think, to reason, and to reach conclusions; it means to concentrate and to work hard.
To think, then, is to cerebrate.

To worry is to cerebrate intensely.
Worry is overwork of the most disastrous kind; it means to drive the mental machinery at an unreasonable and dangerous rate.

Worry gives the brain no rest, but rather keeps the delicate cells in constant and continuous action.

Work is wear; worry is tear.