If you truly live the culinary world, your learning and mastering of the skill(s) has no limit on time. You should always be a constant student of this game and get all you can from it to make you that much stronger at your craft.
Formal culinary school 3 years including internship. But culinary learning is not bound by time, food evolves and so must we.
Once you start a culinary career, the learning and improving never ends,