Bullied at school, one girl took severe exception to me. She was my first nemesis
First job, the woman one step up from me was supposed to be my mentor. She sabotaged me at every opportunity. My second nemesis
Then PoisonousSIL - whose mother introduced my DH to the priest who would be marrying her as "the brother she should be marrying" - I'm front of the whole family! Nemesis 3+4
Head of another department objected to the fact that my teaching subject overlapped with hers - she nearly killed off my teaching career in year 1. 5th nemesis
Same at the last teaching job I had. She now runs the dept I helped set up and is described in all the college bumf as the woman who single handedly grew L3 provision to it's excellent state. Nemesis for many, she was/is incredibly dangerous if you aren't one of her chosen disciples.
Now self employed and don't have one.
I was discussing it with a friend a year or so ago and we decided that my rather naive, helpful, generous nature is seen as incredibly suspicious by some. I happily share ideas and resources without question... some people always look for the catch and, when there isn't one to be seen, assume I am up to something behind their back.
And I'm daft enough to be oblivious!
My only advice is to enjoy them... they can be quite ridiculous. Recognise their weakness and don't let it get to you.