I have a bad opinion of myself. You can't tell because I write books, I do a lot of talks, I run this news website: plainly I have an ego. But you can probably guess. I'm a writer, the collective noun for us is neuroses. Sometimes this opinion of me gets in my way and I wrote recently about how criticising oneself in the third person is surprisingly more successful than doing it the usual “I bollocksed-up there” way. (I liked that post a lot: Must Do Better.) Now there's more.

Now there's the idea that you just change yourself to fix this bad opinion:

Let’s say you want to become the type of person who never misses a workout. (If you believed that about yourself, how much easier would it be to get in shape?) Every time you choose to do a workout — even if it’s only 5 minutes — you’re casting a vote for this new identity in your mind. Every action is a vote for the type of person you want to become.

How to Change Your Beliefs and Stick to Your Goals for Good – James Clear

It's not the greatest of reads – Lifehacker's coverage of it is better – but try the full post.