If you've never taken your Myers-Briggs personality test, it's something I recommend doing. Not that it will forever change you or how you operate in day-to-day life, but it is important to know that many of your strengths, weaknesses, and leanings originate from your personality.
For example, I'm an ESFJ. This means, I'm an extrovert (E), sensing (S), feeling (F) and judging (J). But what does that really mean? We ESFJs are people persons! We are interested in others, and use our sensing and judging characteristics to gather information on others, to in turn be used as supportive judgments. We like people, we want others to like us, and we have a skill for bringing out the best in others. Moreover, we are extremely good at reading others, and understanding their point of view.
By knowing this about myself, I am able to use the key features of my personality to my advantage. Likewise, I'm also able to know where I may falter and what will be hard for me. For example, for an ESFJ we tend to take criticisms poorly. ESFJs are so conflict-averse that we can become very defensive and hurt if someone, especially a person close to us, criticizes our habits, beliefs or traditions.
So what's my point, you ask? It's so imperative, in my opinion, to know this about yourself when it comes to business. I know that I am afraid of rejection, so for me cold-calling or anything similar is THE ABSOLUTE WORST. That's because I know that cold-calling usually results in a lot of rejection. So, when it comes time to do this, I have to plan strategically. I have to do it first thing in the day, and I have to give myself goals to reach, so that even if everyone says no, I'll still have met my goal by calling, say, 25 people that day...thus resulting in some type of win and not just a solid wall of rejection.
It's also important to know your personality type in a larger sense with regard to business. If I had chosen the profession of analyst I would very likely be miserable. That's because I thrive off of human interaction, being apart of a team, and basically 'gettin' shit done'. While I have nothing against analysts, that type of career would have been all wrong for me. Sometimes it's hard though, and you have to actually do the job, hate it, and then realize it's not the job for you. Sadly, life is trial by fire sometimes, and even a Myers-Briggs test won't prepare you for that.
So to summarize, I truly do believe that knowing your personality type will help you become a more efficient and effective business person. And don't forget, knowing what the OTHER types of personalities are is also crucial. It's nice to know how other people operate since you're not likely to be working completely isolated from others.
There are plenty of free personality tests out there, but to take the Myers-Briggs you will have to pay. If you want a quick, and easy one, I recommend:
This is a different take on the personality test, and done by choosing images that you think aligns with your answer to the question. It does take a bit longer than the previous one: