Do you like voicing your opinion?
Do people often tell you you're long-winded?
Do you consider yourself organized?
Do you know a lot about any particular topic?
If you answered yes, yes, yes, and obviously, you're prime for writing a treatise. A treatise is just a long, formal (i.e., organized) discussion of any given topic. Authors of treatises really dig deep and focus on the principles of what they're discussing.
P.S. Treatises tend to be longer than an essay, but shorter than a… giraffe. What—you don't believe us? We dare you to measure a treatise against a giraffe.