If you're over the age of say, 25, prepare to feel ancient. Fine Brothers Entertainment just released a video where they show teenagers reacting to encyclopedias, or as one teen calls them, "the internet in books."

Just in case you don't know what they are, encyclopedias are set of books that has information on many subjects, from lions to the House of Representatives to Leonardo da Vinci's art and more. They're what most students used for papers before the internet became everyone's source for everything.

The teens' reactions in the beginning of the video are pretty hilarious since a lot of them hadn't ever seen the set of books before. One of the teens asked if he had to read all of them. (Yes, yes you do. And afterwards, plz read through the whole internet.)

Only one teen knew what they were actually called. Others guessed they were atlases or almanacs, probably because those were the only type of super-old book they could think of.

The Fine Brothers also asked the teens what they use instead of encyclopedias, and one enthusiastically answered "Wikipedia!" So, for those who use Wikipedia as their only source for papers, a PSA: anyone on earth can edit Wikipedia, even people younger and less smart than you.

To get the most reliable information on the War of 1812 or cell division or whatever, one of your best bets is still the dusty old library. If you still think books are way too heavy or something, you can also use Google Scholar, a search engine that assembles reputable sources of information from scholarly books and peer-reviewed journals.