I just checked and it was 1996 for me as well. I started with DLD and a 2.0 kernel. Man, those were hard times. There was no internet, I could only dial into a BBS, where I could chat with people who were using Linux. If I had problems setting up dial-up? Well… Also getting a printer to work still haunts me to this day.
Docker is a set of tools, that make it easier to work with some features of the Linux kernel. These kernel features allow several degrees of separating different processes from each other. For example, by default each Docker container you run will see its own file system, unable to interact (read: mess) with the original file system on the host or other Docker container. Each Docker container is in the end a single executable with all its dependencies bundled in an archive file, plus some Docker-related metadata.