As kelseyfrog commented already, the key is to focus on the action, not the target. Lifting is not just about hitting a number or getting bigger muscles (though they are great extrinsic motivators), its more of an action that we derive growth from. I have internalized the act of working out that those targets are baked into the unconscious. I don't overthink when I'm lifting. My unconscious take the lead, and I just follow. I enjoy seeing the results show up unexpectedly. It lets me grow without feeling the constant pressure of my conscious mind.
The lifting analogy can be applied to writing and other effortful pursuits. We write for the pleasure of reconciling internal conflicts and restoring order to our chaotic mind. Writing is the lifting of our mind. If we do it for comparison, then there's no point in lifting, or writing, or many other things we do after all our technological breakthroughs. Doing what we do is a means to an end, not the other way around.