When I was 13 and at boarding school, a friend wrote me a note saying that she couldn’t be my pal any more. The reason? She was jealous of me and felt this was bringing out the worst in her (I already knew she had been talking about me behind my back).Her note – which was tremendously self-aware, to be fair – said it was too hard to be friends with someone who had ‘everything’.She was jealous that I had lots of beauty products and trendy clothes, even though I did share these with her.I’m not sure I had everything, but I did have a mother who took me shopping at Boots and Topshop at the weekend, which was the height of envy-inducing sophistication in 1994.Today I admire that teenage girl’s honesty but, at the time, I was devastated that our friendship couldn’t withstand resentment provoked by Rimmel frosted eye shadow.As a teenager, losing a close friend was heartbreaking and it took quite a long time to get over it. We are creatures of habit and, whatever age you are, someone disappearing from your life often feels jarring, empty and sad.Unfortunately this wouldn’t be the last of my friendships to wilt under the desert heat of jealousy. A few years ago and rather more seriously, another friend, who I’d met through my children years before, confessed she was jealous of me and was trying desperately not to be.She said it was because I wasn’t scared to be myself and speak my mind and that her envy was warped by some sort of admiration. Oprah Winfrey says that if there is even one iota of jealousy between two people, you can’t be friends and, in Sybilla Hart's experience, that’s trueThe truth is, I don’t think I am any more outspoken than this jealous friend of mine and she’s certainly not the shrinking violet she thinks she is, but once jealousy is on the table, it’s hard for a friendship to survive.The good feeling between us soured. It was a shame, but we both felt it and the friendship fizzled out.Jealousy is a strong spiritual emotion and, at its core, very destructive.Oprah Winfrey says that if there is even one iota of jealousy between two people, you can’t be friends and, in my experience, that’s true.Sadly, it’s oh too common among women. Some would argue that this is a result of internalised misogyny but I suspect it might just be in our nature. Women are just more jealous than men.Perhaps there’s an evolutionary reason for this, with jealousy acting as a sort of early warning system that someone was trying to steal your caveman, leaving you and your children vulnerable.But, allowed to run rampant, it can infect all areas of your life.Believe it or not, the ‘friends’ who admit they’re jealous are actually the good ones. At least you know where you stand. Jealousy is a strong spiritual emotion and, at its core, very destructive, says Sybilla, and allowed to run rampant, it can infect all areas of your life (Stock image)Jealousy is often referred to as the ‘green-eyed monster’ but I’ve found it can also bring out another frightful character: the pesky, silent ghost.These ‘ghosters’ go totally silent on you, no matter how many times you try to contact them or how firm a friendship you may have had.Ghosting is a jealous person’s favourite weapon, as it makes the other person feel insecure and they love nothing more than undermining those they’re envious of.When my children were little, I had an amazing housekeeper who, after 18 months with us, had become what I considered a good friend. We got on really well and there was a lot of kindness on both sides.If I had morning sickness, she’d make lunch for the children so I didn’t have to be around food. If she needed to get home earlier to her kids, we were always flexible.Then, all of a sudden, her attitude towards me changed.One morning I couldn’t get a smile or a word out of her and the next thing I knew, she was trying to turn my au pair against me by telling her it was an awful job for which you got no thanks.This was ridiculous. It became obvious not long after that the real problem was jealousy, as I was pregnant at the time and she desperately wanted a third child. She left shortly afterwards of her own accord and I felt deeply saddened.Recently my 14-year-old daughter said something to me about jealousy which was so wise beyond her years, it made me cry. She said that if you’re not going anywhere, people won’t bother you, but if you are flying, some people will hate you for it, and you have to discard those people for your own wellbeing.So, as someone who knows first-hand the devastating impact jealousy can have on friendships, my advice is: let them go. Don’t call them, don’t plead, don’t go poking your head in the hornets’ nest. True friends will cheer your success.