The world is full of myths. Most of them are harmlessly inaccurate—like the image of Vikings wearing horned helmets (we have 19th-century operas to thank for that). Some are simply discredited facts that have hung on through repetition (go ahead and put your car battery on the garage floor; we promise it won’t lose its charge).

But persistent myths about the sales profession are anything but harmless. In our work with sales forces from every industry and across the globe, we have found that myths can take down a promising career faster than a penny dropped from the top of the Empire State Building. We’re not talking about ancient stereotypes held by people outside the profession. The most damaging myths about sales are held by a surprising number of intelligent, well trained people who sell for a living.

Have you fallen for any of these sales-related urban legends?

There’s a best way to set goals. Most salespeople are awash in goals: revenue goals, team goals, time-management goals, stretch goals. Maybe everyone on your team has exactly the same goal. Why do some meet it while others don’t even come close? Maybe they’ve bought into a common myth about goals—that there’s only one way to set them.

Goals are multifaceted. Within every productivity goal, you’ll find a defined result (variously called a target or intention); an active pursuit, involving specific behaviors toward the result; and some kind of conscious strategy for effectively matching actions to targets. Most goal-setting programs prescribe that you pay equal attention to defining intention and tracking pursuit. Many people find this helpful. But not everyone works best that way.

Some salespeople are strategists: They want to focus on the big picture, the result, and be left alone to achieve it. Filling out daily call logs drives strategists crazy.

Other salespeople are tacticians. Selling is a numbers game, and they know that if they meet daily or weekly targets for contacting prospective buyers, sales will follow. Having to formulate broad or long-term goals may be counterproductively intimidating to a tactician.

Problems arise when strategists and tacticians are forced into a rigid approach to goal setting, which can leave people struggling to follow a formula that doesn’t fit them. Additionally, training and management support often address only part of the goal-setting equation. Setting goals should always work for the salesperson, not vice versa.

Everyone likes incentive programs. Free trips! Gift certificates! Recognition ceremonies! Sales organizations love to motivate people through contests and awards. That’s why every salesperson makes quota and wins a prize. Right? Of course not.

The real story behind this sales myth isn’t that prizes and short-term incentives don’t work. That’s overly simplistic and not necessarily true, as some high-producing salespeople report feeling highly motivated by the promise of a reward. The truth is more complex.

In a study of more than 3,000 salespeople in the real estate industry, 70% indicated they preferred some kind of reward-based strategy to encourage increased sales. With that level of support, it’s no wonder contests are prevalent.

Unfortunately, preferences aren’t results. The study also revealed that those same sellers were significantly less comfortable with actually prospecting for new business. In other words, they were less likely to support their desire for rewards with behaviors that would earn them. Meanwhile, the 30% who indicated they didn’t want or need a contest were more likely to engage in sales-supporting activities (and thus, ironically, were more likely to produce results that would be rewarded).

Incentives can be an effective means to translate productivity into tangible rewards, or they can offer the icing before the cake. If you find sales contests appealing, great. Just make sure they provide a clean target and yield results.

Experience is the best teacher. Probably every salesperson has heard some variation of this promise when getting started: “The more calls you get under your belt, the more comfortable you’ll be.” Or, “Once you know the product inside and out, you won’t have any problems.” It’s true that repetition and training go a long way toward calming jitters related to inexperience. But there’s an unspoken assumption behind those promises—that veteran, knowledgeable salespeople don’t (or shouldn’t) feel uncomfortable with the selling process. Sadly, we know that isn’t true.

Emotional discomfort with selling, from prospecting to group presentations to closing, can strike at any point in your career. In the incentive study above, for example, we found that the relationship between rewards and hesitation to prospect remained stable whether the salespeople in question were new to the job or had five-plus years of tenure. Experience doesn’t immunize.

Being unable to consistently initiate sales contacts takes a direct hit on your earning potential. But what can be even more costly is struggling with the belief that your discomfort reflects your skill, knowledge, potential or value. Some salespeople abandon the struggle without ever achieving success. Others try to disguise it, waiting for years (even decades) for the magic moment when their experience will wipe out their pain.

When it doesn’t, they might walk away from a financially successful career rather than continue to fight it. We call it the “Quits While Succeeding” syndrome. It’s brought more than one brilliant sales career to a premature and unnecessary end.

While experience isn’t a magic potion, it can be a wise teacher. Whether you measure your tenure in weeks or years, always be receptive to the lessons of experience. If a technique lauded as “sure-fire” doesn’t work for you, drop it. If you discover a tactic that feels right and makes a difference, no matter how unorthodox, invest in it. Never stop refining and reevaluating your skill set, because the notion that a good salesperson is ever fully trained is just another myth.