"I AM SOMEONE WHO..."
A mindset shift I feel is important (and I continually need to work on) is changing from an “I am a [blank]” to “I am someone who [blank].”
For instance, instead of your goal being “I run a marathon in 3 hours,” have your goal to be “I am someone who trains to run as fast of a marathon as I can.”
You might find that defeating if you wrap up your identity into the end metric.
There will always be someone faster, or more wealthy, or whatever your metric is.
Instead, identify with the journey.
Identify as the type of person who always pushes your envelope, seeks to achieve more, and is constantly pushing your boundaries.
It’s a subtle mindset shift, but for me, it helps take my ego out of the comparison game.