Clark is very impressed with young people who open a 401(k) when they first start a job. Years ago, few people even knew what a 401(k) was!

But a new study from Fidelity reveals that just under half of all 20somethings and 30somethings cash out their 401(k) accounts when they change jobs.

That's like snatching defeat from the jaws of victory.

As regular listeners know, retirement savings need time to grow. That idea is well illustrated in Clark's retirement chart.

Know that the money you cash out of your 401(k) gets hit with penalties of about 40%. So Clark's special challenge to younger people is for them not to cash out. Instead, think about rolling your money over to your new employer's 401(k) plan.