You may notice while you are training someone that your combined productivity rate goes in the toilet for a while, but that your wage continues to be paid. If you were the boss, this would mean that you would be working overtime to still complete the work until the new employee becomes productive enough to help attack the pile of work.
Believe it or not, work is not the be all and end all of your life. It is a diversion. YOU need to have a life, and take vacations, because at the end of the trail, work is a means to an end, not the end in itself. A new trainee can help you get your life back.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)