@w3c Well, at least the shirts are accurate?

"The word Internet was used in 1945 by the United States War Department in a radio operator's manual, and in 1974 as the shorthand form of Internetwork."

Or sometimes: Intergalactic Network of Computers.

IMHO, "The Internet" did not begin with TCP in 1983.

Moreover, I'd posit that Dr. Marshall Kirk McKusick, who was largely responsible for the implementation of what is now often termed the BSD TCP/IP stack while he was an undergraduate at UC Berkeley working with the CSRG had a LOT more to do with TCP being deployed (also see the BBN BS recounted here):

youtube.com/watch?v=DEEr6dT-4u

Computer networks go back to at least SAGE [Semi-Automatic Ground Environment] from the 1950s, but the Internet largely evolved out of NLS (oNLine System) from Doug Engelbart's Augment group at SRI in the 1960s, particularly after J.C.R. Licklider gave them (D)ARPA funding; albeit at that point in time, it ran NCP (Network Control Program). TCP "flag day" wasn't until 1983, but "the Internet" was already in operation with RFCs, FTP and more, long before then.