I still remember discovering FidoNet sometime in the 90s.

It was a time where sending regular mail to different countries could take weeks, and cross country phonecalls would cost between $2 and $20 per minute, and here was FidoNet that promised to allow communications across the globe with only 1-4 days delay and basically for free.

My 15-18 year old self was instantly sold. I spent countless hours reading through the "forums" on there. So much knowledge just at the tip of my fingers.

Of course some time later it was more or less replaced (for me) by email, usenet and IRC, but the memory still remains.