Privacy settings on social networks have limited value. They are confusing to configure and change often. Ultimately, if you do not want your parents or boss reading it, do not post it.
To learn more, check out this OUCH! newsletter: https://securingthehuman.sans.org/newsletters/ouch/issues/OUCH-201507_en.pdf
More cybersecurity education available here: https://www.youtube.com/playlist?list=PLQNZaWpmI1TfMOQMJ-ra1VSGgkuOPtFlA