Ha! I remember doing that same thing for someone! We had to take a photo for a school album and because ties were a part of our uniform we were told to wear ours for it, but it was optional to wear it at school so nobody usually wore it. I was one of the only people who knew how to tie a tie.
...but unfortunately they were all guys...and I'm a guy too. I couldn't tie it from the front so I had to embrace all of them from the back to tie their ties. lol