You worked your keester off at your job. Finally, finally, you’re reaching big accomplishments. And the success? It tastes oh, so sweet. Except, of course, that certain people around you have started to treat you like you kicked their puppy, told them Santa Claus isn’t real, and sold your soul to Lord Voldemort, all on your lunch hour. What gives? Seriously, why can’t they just be happy that things are going well for you

1. They have inflexible expectations.

According to research led by Lauren Leotti, and echoed by psychologist Susan Weinschenk, people have an innate need for control. Having a sense of choice and power provides both psychological and physical benefits, because it reduces the stress you feel and makes you more confident in your odds of survival. At the same time, research led by psychologist Jason Plaks demonstrates that people get anxious when performance doesn’t meet their expectations, mainly because the results disrupt their perception of being in the driver’s seat. This holds true even when the outcome they’re experiencing is good for them.

“People are driven to feel that they can predict and control their outcomes,” Plaks says. “So when their performance turns out to violate their predictions, this can be unnerving–even if the outcome is, objectively speaking, good news.”

2. They feel inadequate.

As psychologist and author Steven Berglas asserts, people look to others for a benchmark by which they can gauge their own success. When you change the benchmark in such a way that you are now above where they are, they start questioning their own skills and abilities and feel like they’ve failed. This sense of inadequacy can be made even worse by the fear that, as you gradually make choices that create more distance, you’ll leave them behind.

3. There’s pain in their past.

In some instances, people reach hard for their dreams only to fall short, often through no fault of their own. And some individuals honestly have been kicked when they’re down through various types of abuse. When you go up another rung on the ladder, it’s like you throw all that back in their face. They don’t resent you, per se, because they know you’ve worked hard, too, but their sense of fairness makes them sad and angry that others can do well when they still feel trapped.

4. They’re angry at themselves.

Some people who see you succeed will recognize all the tough stuff you probably went through to get where you are. They’ll acknowledge that your success came with sacrifice–that they weren’t willing to make. So they get upset with the choices they made, understanding that they could have stood where you are if they’d had a little more courage or perseverance. In a broader sense, they can get frustrated that they’re stuck in a specific way of living that holds them back.

5. You’re destroying their concept of the rules (and themselves).

In the United States, the mantra is, if you work hard, if you’ll move forward and the proverbial American dream will come within reach. That concept frequently goes hand in hand with a stress on integrity, emphasizing that you shouldn’t cheat to pass the other guy. But when they work just as hard as you do and you come out the winner, suddenly, you make them question these rules. That, in turn, can lead them to question just about every other social construct out there and lead them into a real crisis of behavior and self. Protesting your hard-earned good fortune is their way of resisting that chaos and convincing themselves that what they lived and believed was truth.

When you’re successful in your personal life or work, you have a right to feel a sense of pride about it. But not everyone is going to share your good feelings. Their reasons for being the classic party pooper, however, can connect to incredibly deep emotions and psychological needs. If someone seems bitter toward you as you meet your goals, keep those feelings and needs in mind so you can react in a way that’s both appropriate and compassionate.