When was the last time you had one? I'm talking artistically, which means that you should be able to overcome and turn it into motivation/inspiration if you know what's good for you. An artistic kick in the ass.
I've had a few minor ones these past months, but fresh in my mind is the Spectrum show at Society of Illustrators. If anything ever made me feel like I'm not working hard enough... I think there's actually still a red mark from where it kicked me. As of today I'm redoubling efforts.
What about you all, I know that it's happened to all of us and a number of times!