No greys yet at 33, but I get my hair cut every 2 weeks. A few months ago I go to my barber for the same cut I always get. He starts cutting my hair and go's holy shit dude, your hair got thin quick in 2 weeks. Now I can see a thinner line around my head. WTF how did my hair go so thin in just 2 weeks. Hasn't gotten any worse in the past couple months though.