# Jimism #002: The Half-Life of a Skill
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## Article Content
Your expertise now has an expiry date. There was a time when you could learn a profession in your twenties, master it in your thirties and forties, and spend much of the rest of your career benefiting from what you already knew. That world is disappearing. The half-life of a professional skill has collapsed dramatically. Knowledge that once remained valuable for a decade or more can now become outdated within just a few years. AI is accelerating that even further. That's why one of the most dangerous phrases in business today is: "I'm an expert." The better phrase might be: "I'm becoming an expert again." Because the strategic advantage isn't simply what you know. It's how quickly you can learn what you don't know yet. Three ways to respond: Measure learning velocity. Stop asking only what someone knows today. Ask how quickly they can become competent at something entirely new.Build unlearning into the job. Some of the knowledge holding you back was once perfectly correct. That's what makes obsolete expertise so dangerous.Reward curiosity. The employee asking strange questions about an emerging technology might be more valuable than the employee confidently defending yesterday's process. This changes the definition of experience too. Twenty years of experience can be extraordinarily valuable. Or it can be one year of experience repeated twenty times. The difference is whether you kept updating the model. Your skills have a half-life. So does your strategy. So does your business model. The question isn't whether some of what you know will become obsolete. It will. The question is whether you will notice before everyone else does. jimisms.jimcarroll.com

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Source: https://jimcarroll.com/2026/09/jimism-002-the-half-life-of-a-skill/