Guillermo Mota returned to the Mets yesterday afternoon, having served his 50-game suspension for violating Major League Baseball's drug policy. The 33-year-old called his violation "a mistake" and, when asked if he would ever do it again or if he learned his lesson, answered, "Of course, I've learned my lesson." Mota, who did a pregame interview in the dugout, also tried to lighten the mood. When one reporter said many fans didn't know whether he was a good guy or a bad guy, Mota replied, "I'm a good guy."