At the end of the episode, Ted, Barney, and Robin go to a strip club to cap off their Thanksgiving.
After paying for a homeless man’s lap dance, a stripper introduces herself to Ted at the buffet. She says her name is Amber.
After Ted introduces himself to her, she leans in and says, “Actually, I’m Tracy.”
Cut back to the voice over narration and Ted says: “And that, kids, is the true story of how I met your mother.”
The kids panic, and yell in unison “WHAT?” before Ted explains that he is kidding.
They are so shocked because their mom’s name really was Tracy.