"My manager and I both agreed that my advancement opportunities were limited there and obtaining another position was best option for me and my career goals." Be prepared for a possible follow-up question such as "What ARE your career goals?"

"I wanted more challenging assignments." This is a nice way of saying you were bored out of your mind. Prepare to follow it up by saying something about being eager to tackle challenges associated with position for which you are applying.

"I'm looking for an organization that supports its people." This could trigger "Can you expand on that?" question, so be sure to have a response planned, such as "There weren't many training opportunities."

"My career goals have changed." This is a great response if you are going into a new field. However, companies want people who can hit ground running, so be prepared to explain how your past experiences make you a good candidate for this new job.

One or all of these may be variations of real story, so you won't really be lying about why you left your last job. You just won't be giving them whole truth!

When this happens, your boss will not appreciate your excuse: "But I had too much to do, I was overloaded with work!" Saying that AFTER fact will be much worse than telling your boss up front -- before mistakes occur or deadlines are missed -- that you're having trouble with your workload.

It is your responsibility to tell your boss when you are overwhelmed, and there's nothing wrong with doing this.

Of course, you don't want to tell your boss, "I can't do that; I'm too busy." But you can say, "I'll be happy to take that on, but I need your help with prioritizing other projects you've already given me. Which jobs can I put on hold or delegate to someone else while I work on this new one?"

That's way better than keeping your mouth shut, trying to do too much, and failing miserably.