Actor-filmmaker Kamal Haasan is "sorry" for riding a bike in his forthcoming Tamil thriller "Papanasam" without a helmet, but says it's common sense to wear one when one steps out on a bike."We shouldn't have shot the bike scenes without a helmet, and I'm sorry for it," Kamal told IANS.A poster featuring a helmet-less Kamal riding a moped along with co-stars Gauthami, Nivetha Thomas and Esther, has received a little flak from audiences, especially after the Tamil Nadu government made it mandatory to wear helmets all those who got on a bike."We shot the bike scenes long back, but that's not much of an excuse. We should've definitely thought of using a helmet. But I think it's common sense to wear a helmet when you step on a bike, just like you wear slippers while getting out," he said.Directed by Jeethu Joseph, "Papanasam" is the remake of Malayalam hit Drishyam. It is slated for release on July 3.