Subject: Why does burning hair smell so bad?

You know, it seems like most things that burn smell pretty good. There's a few
things that don't smell good while burning, rubber, plastic, etc. but, it's
funny that things like wood and paper tend to smell pleasing while they are burning.
However, human hair smells "uniquely terrible" while it's burning. I was just
curious what it is that makes it smell so bad compared to things like wood.
Thanks

Re: Why does burning hair smell so bad?