Related: The most amazing 401(k) participant conversation ever

Let's take a step back for a moment. In the tradition sense of legal trusts, the trustee was named as the fiduciary on behalf of the beneficiary.

The beneficiary, for one reason or another, was deemed not capable of acting in their own best interest. For example, many beneficiaries were underage children, so it was understandable that the trustee would serve as the surrogate parent until the child came of age.

Sometimes the trust document was written in such a manner as to define "coming of age" as well into adulthood. That meant the trustee still retained decision-making authority over the beneficiary despite the beneficiary being old enough to make his own decisions. This can be awkward and acrimonious, but the law sided with the trustee.

I greatly doubt very few readers find themselves in the being of being a legal trustee from some unwilling ward. Most, however, do fall under the umbrella definition of "fiduciary" and therefore have a duty to act in the best interest of clients, no matter how unwilling they are.

The more obstinate the clients are, the more difficult the job of the fiduciary becomes.

How, then, can a fiduciary "train" clients to serve their own best interests?

Research in behavioral science will tell you there is no sure-fire method. You can lead a horse to water and even get him to drink… today. There's no guarantee that horse will remember to drink tomorrow.

That's why those annual employee meetings are so important. While the seeming repetition can get boring, especially for the more attentive employees, it's needed to recharge the retirement-saving-thinking process. Remember, unlike the professional, retirement plan participants don't have a job that requires them to focus on retirement saving every day.

Or do they?

Here's a trick I picked up as a Boy Scout leader that I've applied to employee education meetings. The concept is simple: The best way to learn is to teach.

In Boy Scouts, after the Scoutmaster explains, demonstrates, guides, and enables a boy to perform a specific task (e.g., how to dress a wound, how to tie a knot, etc…), the boy then turns around and teaches a younger boy how to do that same specific task.

Soon, after teaching enough boys over and over again, that task becomes second nature, so much so that the boy will remember how to do it when he's a man (and even a Scout leader for a new generation of boys).

You don't (and shouldn't) hold employee meetings with the same frequency as a Boy Scout troop meets, but it doesn't mean you can't apply the same technique. Once you've shown retirement savers how to think, decide, and act correctly (including how to ask the right questions), your educational meetings will become repetitive. Attendees will lose interest and eventually forget to drink that water you led them to. How do you overcome this?

Ask them to teach what they've learned to someone else. Better yet, make it a homework assignment and have them report back to you at the next meeting. Provide all the necessary worksheets to them so they can document their progress as teachers.

Sounds great, right? Of course, saying this is one thing. Actually getting them to do it is another.

One of the biggest obstacles people have to "teaching" is determining who their students are. You'll need to guide them, here, too. The best students are kids. Have them start with their own kids, their grandkids, and their nieces and nephews. Noticed that I said "kids" and not "children."

These family members can be children, young adults, or even adults. Indeed, the older the student, the easier it will be for the teacher to teach (and reinforce their own learning).

After family members, scouts might be the next best group. Boy Scouts and Girl Scouts are always looking for merit badge and badge counselors. The Boy Scouts has the Personal Management merit badge while the Girl Scouts offer a series of Financial Literacy badges.

Once employees start on the road to teaching others, you can be sure they'll be less likely to be distracted by the latest investment fad and keep focused on their own retirement saving.

Who knows, if you're really good at converting retirement savers to retirement teachers, you'll not only play the role of retirement-saving fiduciary at the annual employee education meeting, you'll also play the role of retirement-saving missionary.