[Amorymeltzer]

Probably depends on your age and other characteristics. If you can be called a millennial, a 2013 study (http://www.emarketer.com/Articles/Print.aspx?R=1009748) found that there's over an 80% chance you use social media. That goes down each previous generation, so a baby-boomer should be expected NOT to have such things.

Also, other factors are probably relevant. "No twitter" is very different from "No twitter, because I'm married with twins."

[pluma]

It's important to remember that "80% chance you do X" also means "20% chance you DON'T do X". And "20%" means "1 in 5".

We like to conflate large percentages as "practically 100%" but even ".1%" just means "1 in 1000". For large groups even low percentages can represent a significant quantity.