I shave my arms every now again and my friends freak out when I tell them why my arms are so smooth. They always yell it out loud in the cafeteria. I don't need to remember if my friend shaves their arms or not but you don't to yell aloud (even if I think it's hilarious when they freak out). I think arm hair grows back much slower than arm hair and if it grows back thicker just buy another razor you'll be fine. My hair didn't grow back thicker in fact I think it gotten thinner over time so there you go.