> Likewise, we began to "load" stuff, not "up" or "down", but to the "side".

In the early or mid 2000s, I remember using a file hosting service which advertised sideloading as a feature — by that, they meant you could paste in a URL of a file on the Web, and the service would download the file directly into your storage space, skipping the need to download to disk first then upload from there.