1) I'm self employed. 2) I'm always connected via a VPN connected to a continent that isn't my home continent. 3) I haven't connected to the internet via a "company" network in over five years.
I could infer that you are male from the way you type, and I guess you're somewhere between 25 and 35. I haven't looked up your username or anything else, it's just a "feeling".
Given millions of paragraphs of text linked to millions of known demographic and other data points (provided by Facebook), a paragraph is all a well-tuned system would need to make quite accurate assumptions about the person who typed the paragraph.
Again, likes are not required anymore.