I Had Always Thought,

that Facebook and other social media were modern inventions,

but I was wrong, by many hundreds of years, it works like this, young people in France, Germany, and the Netherlands would keep journals called alba amicorum, which translates from Latin to 'friend books',

young men would use them to document their travels and education, and have teachers and experts write -or draw- in them, almost like latter day autograph books, they could eventually be used as resumes, some of the earliest of these date from 1560, 

girls or young ladies made their own books, and had their friends add art, poetry, and personal notes to them, they became a document of events and relationships, I wonder if these books, many of which survive is how Facebook became to be named?