I asked 200 retirees for their best advice. The biggest tip had nothing to do with money.

Sam Drew for BI

Most 24-year-olds aren't thinking too deeply about retirement. With decades of work ahead of them, most are focused on getting their footing in the workplace — not on the financial needs and life goals of their 65-year-old selves.

The same was true for me. Sure, I enrolled in a 401(k) and started to build an emergency fund, but I hadn't really sat down and mapped out what my future would look like 40-some-odd years down the road. That all changed recently.

Over the past several months...