Why are people disgusting?!?!

So yesterday on the train ride home this lady had a runny nose and I watched her look for a tissue then proceeded to lick it off her upper lip!! I mean if you really can't find a tissue, don't lick it!! Wipe it off with your shirt discreetly or something!! But as gross as that was it doesn't come close to what I saw today!!  So this morning I am sitting on the train and the girl (mid to late twenties about) starts picking her nose AND eating it!!!!!!!!!!!!!!!!!!!!  This did not just happen once....it happened many times and if you know me well you know I tend to gag when I am grossed out, so I am trying to not look at her while she does this repeatedly....and it's not like she didn't have a tissue, because she had some and blew her nose once or twice....but then stopped to pick it some more AND EAT IT!!!  I am actually gagging while I write this I am so horrified!!  I had to put my ipod on loud and close my eyes to avoid seeing this horrific sight....my god!!!!! Blehhhhhhhhhhhhhhhhh