ISFP if you are curious) but thought it was time to revisit where I am now, and perhaps where I've been in the past.
When we gain better knowledge of ourselves, we are better able to conquer our faults and disordered attitudes/attachments which often can cause us to sin. Having a deep knowledge of self is one of the best ways in advancing in the spiritual life and toward the perfection that Jesus calls us to; always with the help of His grace of course.
One of the ways in which to do this, keep in mind this is only one, is to study the temperments, and find out which one describes you best. There are four: The Choleric, Sanguine, Melancholic, and Phlegmatic. Most people are a mixture of two. I highly recommend taking some time to read Rev. Conrad Hock's The Four Temperments which can be found online in full text. There is a test at the end which you can take to better help you discern which temperment(s) fit you. It's also wonderful because he looks at it from a Catholic perspective.
I also found some good summaries online of the four temperaments by Fr. Antonio Royo Marin, O.P. Here is Post I on the Sanguine and Melancholic, and Post II on the Choleric and Phlegmatic.
Happy discovering. :-)
P.S. I had a curious mixture of the four temperaments, but my highest score was predominantly the melancholic.
"People travel to wonder at the height of mountains, at the huge waves of the sea, at the long courses of rivers, at the vast compass of the ocean, at the circular motion of the stars; and they pass by themselves without wondering."
"Know thyself, or at least keep renewing the acquaintance."