Is it normal to be able to trim your toenails with your bare fingers?

Most people use toenail clippers or scissors when they trim their toenails - I can just pull the excess toenail off with my bare fingers. Is this abnormal? I'm 20 years old, of normal weight, with some pretty crappy habits. I don't have any diseases or anything, but I smoke, drink alcohol daily (10-15 units per day) and eat a steady diet of processed food. I never drink milk either. Is that why?