Why do i feel the need to do this?

[sugarspiceetc]

I was good friends with someone who i suspect has narcissistic traits. She made me feel like the greatest friend in the world but then after about 18 months I became devalued and then discarded as a friend. I try to hold no hard feelings towards her, that's her personality, but I do sometimes feel hurt by her actions. Anyway, we both live in quite a small town and sometimes I see her around with her new 'best friend'. Whenever I see them, for example i'll catch sight of them in a shopping centre, I have a desire to spy on them and see what they are doing and how they behave together? I really don't know where this feeling comes from. I recognise it's irrational and I have never acted on it, but only because i have to give myself a good mental talking to. If I allowed instinct to take over i'd be hiding behind trees with a pair of binoculars watching what they do.

I've tried googling for an answer to why this happens but nothing comes up, so I'm turning to MN instead.

You have this thought because you're hurt and confused, which is totally normal. Perhaps deep in your mind you think that if you could only observe her for a while, you would have a better understanding as to why your friendship imploded. Don't worry about having these thoughts. You're not crazy and it's not unusual. You're only human.

I'm sure someone much wiser than me will come along in a minute but I'd say it's because subconsciously you want to see whether she'll treat this new best friend in the same way she treated you. If you see her do the same thing to someone else then it'll prove to you what you already know, that it's all her and nothing to do with you as a person. It's just how she treats people.

Cross post. I'd agree with Aquamarine. It's definitely very normal

Thanks aqua and super for saying that it's normal. I can't see how spying on them would be anything except hurtful as I'd see 2 friends having a good time together. Unless, thinking as I type now, I subconsciously want evidence that new friend is not as good as me.

I think that's what you're looking for - evidence that the new friend isn't as good as you and that your old friend will regret how she treated you. It's always hard to see someone who hurt you seemingly looking happy and care free but all you can do is focus on you. How happy she is (or isn't) shouldn't impact on your happiness.