Trained Noob is a name given to a noob which has been trained thus making him/her better. A noob can not pass the stage of trained noob if he is beeing trained. Ask a great man once said "You can train a noob but he'll just be a trained noob."

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

A trained noob, is a noob gamer who has been trained by a pro gamer. Since pros and noobs have different brain chemistry, the trained noob will never be as good as a pro, but might do very well against other noobs.