Because Brock Lesnar is only a part - timer .
If The Undertaker ever was to actually lose at WrestleMania it would have to be against someone you were aiming to catapult to super-stardom almost immediately .
Because Brock Lesnar is only a part - timer and if The Undertaker ever was to actually lose at WrestleMania it would have to be against someone you were aiming to catapult to super-stardom almost immediately .