Since being around 13 right up to I've noticed that there are some people who seem to love it when you lack confidence, have low self esteem are fat/miserable etc (add your own variation).
When you e.g lose weight (or put it on if you've previously felt too thin), gain confidence/ independence are happy, they try and pull you down. E.g if you've lost weight and gone from fat to normal - you're 'anorexic' or 'not eating anything' - they're on your back.
Alternatively, if you've just had a painful break up they're happy to 'help' but if you're excited about a new relationship you get in a rather clipped tone - "oh well I hope no-one gets hurt" 
They seem in a word to be all over you if you're 'down' but obviously don't like it if you're genuinely confident and happy.
I saw a meme on the Book of Farce
saying "watch out for those who don't clap when you win." I think this is so true - people like this are so toxic. They always also lack confidence - even if their demeanour is not the conventionally 'timid' type and clearly suffer feelings of inferiority- they're not 'happy' people. Well this is my experience anyway. Can anyone relate ?