Well, to bring a bit of balance to this thread...

You know it's going to be a GOOD day when:

Within the first hour of arriving to work, a manager from another dept. comes and asks you to show them in detail what you have been working on because they disagree with the company vice president's opinion on how fast or reliably results can be had (which you've been saying all along).

Then, as soon as they leave, you get an email from a prospective employer asking you to come in for an interview.

That was a double whammy of both feelings of validation and being marketable.