My dad told me his started in his senior year of high school. I have a younger brother...16, and his hairline is starting to diminish. My dad and his dad are the only history, my dad's brothers all have a full head of hair, and my moms dad has a full head of hair along with his sons. There's Indian blood on my mom's side, alot of it, was hoping I would get Indian hair lol. My dad said in his freshman year of college, he would wash his hair and clumps of hair come out. But when I wash my hair, I don't get clumps or massive amounts of hair, just individual strands when I run my hands through my hair. Today...the only hair that I noticed fall out was when I was washing my hair this morning, about 15 hairs came out when I was washing and then running my hands through my hair afterwards, I have been rubbing my head and running my hands through my hair off and on today, and have got a couple fall out, but I don't know.