@nanook - the pain of rejection makes sense in an evolutionary context, doesn't it? i think fear of being outcast or not having a place in 'the tribe' underlies so many neurotic fixations. anxiety and depression are at record highs, it's no wonder in this society of purpose where children must earn their parent's/teacher's approval through deeds. grades are often considered a statement about worth of character, and we are ranked in comparison to each other.
as for what hurts - i think, there's one thing that still gets to me to some extent. if someone i look up to and trust rejects me, especially by comparing me to others and/or replacing me with someone else who they see as 'better', that hurts. there's something especially vexing about being considered disposable/replaceable. like Jenny mentioned, i think it may bother me as it does because of childhood trauma.
I think most of the sensitivities mentioned here can come down to that principle. Humans are essentially pack animals - and the image of the lone wolf, however inspiring and romantic, isn't real. We are strongest in the pack and in the wild would stand little chance of survival alone.
Most people here seem to have experienced rejection from social packs, so this insecurity is accentuated in a different way to most. Most people will follow fashion, trends and common attitudes to fit in but most of us are different enough that we can't seem to get away with this.
For you, it's when you try to establish your purpose within the group using the skills you feel people appreciate most and the insecurity is that this purpose will be surpassed by another more qualified. For me, it's that I'm so used to it I don't bother to try for acceptance and automatically expect rejection. And what actually hurts is when acceptance is found and subsequently taken (or rather, I find out it wasn't real and I was just being used for a purpose and discarded - so I suppose it isn't any different to you).
For Jenny, and some of the others, the fear of being misunderstood and facing rejection because of it. It all comes down to us feeling different to other people - and not automatically being accepted as part of the pack like we see other people.
(Also - it's a lot easier to enter the circle of people who's opinion matters, as I put I, than I make out.)
