I got into Toastmasters (public speaking) to improve my communication skills and after a couple years an interesting side effect developed. I've mentally started turning my list of accomplishments into a "self" speech that I tell myself when impostor syndrome hits and I sell myself to myself. By the time I'm done, I'm thinking "darn straight I belong here!" - a variant on your suggestion.
I'm not an expert on combating impostor syndrome, but some things that have helped me
connecting with others - lots of people can empathize and it helps to talk it out sometimes
finding a mentor - I don't know it all and that's okay
asking for feedback - not for validation, there's a difference (avoid external validation)
give feedback
share ideas
be helpful - when you're busy helping someone work through a design problem, there is no time to worry about whether you belong or not; also it's nice to help someone :D
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I got into Toastmasters (public speaking) to improve my communication skills and after a couple years an interesting side effect developed. I've mentally started turning my list of accomplishments into a "self" speech that I tell myself when impostor syndrome hits and I sell myself to myself. By the time I'm done, I'm thinking "darn straight I belong here!" - a variant on your suggestion.
I'm not an expert on combating impostor syndrome, but some things that have helped me