One thorn of experience is worth a whole wilderness of warning.

Advice slides off; the thing that actually happened to you stays. You can be told a hundred times that the shortcut costs more later, and none of it takes hold until the one afternoon you pay for it yourself. That is not stubbornness so much as how learning works, which is worth remembering before you repeat a warning to someone for the fifth time.

Where you can, let people meet the small version of the consequence rather than arguing them out of it. And where you are the one being warned, ask what the speaker paid to know it, which is usually the detail that makes it land.