And that's when it becomes a problem. There's a reason Impostor Syndrome tends to effect successful people. It's the need to not just be good but to be the best. And if we're not or we feel we're not? It's terrifying. We take less risks, we keep our heads down and hope no one notices we're not actually supposed to be here. Impostor Syndrome isn't a problem because it's an issue of confidence, it's an issue of knowing ones own self worth. We're less likely to ask for a raise, or take on that high risk project and in the worst cases we can shut down completely.
The trick is making Impostor Syndrome work for you. Feeling less like you're going to be found out and using that niggle to push you forward. I was constantly comparing myself to those around me- they were funnier, smarter, they were better writers and I just couldn't see where I fit in. I wasn't sure why I was being offered work or asked to events. When guest lecturing I'd feel like I was just getting up and just word vomiting (when in my mind, nothing short of a TED style talk would do.) Comparing myself to others rather measuring my own success on my own merits was maddening. IS maddening. I mean, I still do it. It's just now it's less all consuming and destructive and more about finding inspiration.
There's a key difference being doing your best and being the best and that's a good a starting point as any. Your successes are not determined by luck and what we do with the opportunities we're given is entirely our own. It takes a bit of mental gymnastics in realising that your self worth isn't tied in to abstract idea of perfection. It's believing that you are good enough. That you are enough. And that's okay.