An internet forum self-image defense strategy. Used by someone has been clearly proven wrong, stupid, or idiotic on a forum over the course of multiple posts or threads. The person realizes how foolish they now look, and default to claiming their entire dialog was a troll. Even though they claim it was a troll, it is very clear and obvious that it was not, and they simply have nothing left to retort with.

When you eat dirt for the first time and leave your family to build a shack in the woods