Finishing 80% of things isn't being 80% complete. The 80-20 rule tells us that it takes 80% of the time to finish the last 20% of a project. So ask yourself, are you afraid of challenge? Is it hard for you to get through hard tasks? Do you avoid that work, the tricky debugging or the digging through docs for esoteric facts?

If so, I get it, that's my tendency as well. The only method I found was to take breaks and think about it in a dissociative state, then I also try to live with boredom. I don't see boredom or frustration as enemies, they are like an itch I can't give in to, because scratching a bug bite makes it even itchier.

To practically improve this way, meditation gave me that extra dose of willpower to last through boredom. meditation simply teaches you to passively observe, it keeps your emotions in check, if you practice enough.