If you’re over 50 and thinking about a career change, you’re not alone — and you’re not indulging a fantasy. The world of work has changed in ways that make the old rules increasingly unreliable.

The careers that once defined success were built for a different era: one where people worked for decades in the same industry, where pensions were relatively secure, and where conformity was rewarded with stability. That trade-off made sense at the time.

But that world has largely disappeared….