Most practice doesn't make you better. It makes you more comfortable.
Anders Ericsson spent his career studying what actually separates experts from everyone else who also put in the hours — and it isn't the hours.
Psychologist Anders Ericsson coined deliberate practice in 1993 after studying violinists at a Berlin music academy, and he was specific about what qualifies. It requires a target just past your current level, immediate feedback on each attempt, and repetition aimed at the exact weak point — usually under a teacher who can see errors you can't. What it explicitly excludes is what he later called naive practice: simply doing the activity again, the way a weekend tennis player rallies for years without ever getting appreciably better.
The distinction explains a pattern Ericsson found unsettling but consistent: experienced surgeons, teachers, and even chess players often plateau decades before retirement, despite accumulating thousands more hours than newer colleagues. Once a skill becomes fluent enough to stop being effortful, most people stop generating the specific, corrective feedback that improvement runs on. The hours keep counting. The improvement doesn't.
This is also why a bad habit can survive twenty years of "practice": repetition without correction just grooves the error deeper.
Hours are the wrong thing to be proud of. The right question is what, precisely, went wrong in the last attempt — and whether anyone told you.