You're confusing "website" and "domain name".

I wasn't there at this time (I'm only 23) but I believe symbolics.com was the first dot-com domain name, not the first website.

Yep, DNS, along with email, usenet, ftp, gopher, and many other internet services were long-established before "the web" was created.

Do you not understand where the web was invented? It wasn't at symbolics.com.

true ..

I think symbolics.com is the oldest (still existing) site / registered domain name

what was the domain name of this (whatever is on the post) site ? when was it registered? anyone??

It's the oldest .com domain, not the oldest domain name