It's imperative that we know ourselves as best we can. Knowing how we tick, why we do things a certain way can shed so much light on who we are as individuals, though it cannot define us entirely. We are all different, of course, though commonalities abound.
Unfortunately, we waste so much time trying to change others, when it's ourselves on whom we should focus. This doesn't mean to avoid offering constructive criticism when necessary, as long as its offered with openness to the other, giving him or her room to discuss how he or she perceives the situation.
While some folks tend to make their Meyers-Briggs Type Inventory and Ennegram information into a religion defining them solely, this is not what the indicators are about. Each gives basic information about a person, and it can liberate a person to know more about himself or herself and others.
I am an INFP (scroll down on linked page for description), yet a 5 on the Ennegram with a 4 wing, which pretty much means that my life's work is to heal others, minister to them. I am deeply concerned with self growth, and am a free spirit who questions everything. As an existentialist, life's meaning occupies much of who I am.
A general dislike of crowds and loud noise seems to characterize INFPs (and me) as well. INFPs also need to recharge after being around others and like to spend time alone. The goal in life is to get closer to balance between the various elements.
On the negative side, Type 5s can be arrogant and scattered when stressed...yup, that's me sometimes, but have worked a lot on these, but always room for improvement!
Famous INFPs include Albert Schwietzer, Annie Dillard, J. K. Rowling, Princess Diana, Jackie O, Mister Rogers, Helen Keller, and Audrey Hepburn. Some fictional INFPs: Winnie the Pooh, Frodo Baggins, Edward Cullen, Fox Mulder, Julian Bashir, and Deana Troi.
This is information I share not to draw attention to myself, but simply to share a little of who I am (a very small percentage of folks share these two types), and also to challenge you to look into taking both the Meyers Briggs and the Ennegram. You can take the online versions to get an idea, but if possible, take each with a qualified person trained to administer and evaluate the results.