Andre Agassi can laugh about it now, but in his first Grand Slam event, the 1990 French Open, the balding future champ was worried sick his now infamous hairpiece — the existence of which was first revealed by Page Six way back in 1993 — would fall off midmatch. Interviewed by Katie Couric for tonight’s “60 Minutes,” Agassi says it “scared the heck out of me. I kept envisioning what this would be like if my hair just flew off and landed. Like, what would I do? Would I go over and kill it, or would I — would I quickly put it back on?” After they stop laughing, Couric asks, “Would you pet it?” Agassi replies: “Would I take it home and name it? . . . I didn’t know what I was gonna do. I didn’t have a plan for what I was gonna do, which is why I was trying to move less and less.”