I don't actually remember the title but in the early 90s I was starting on my journey as a self-taught sysadmin, mainly by being the only person at a tech startup that would work for so little money. Before then I was simply a hobbyist.
It eventually became necessary for me to start passing certification exams. As I was studying for the Windows NT 3.51 exam I bogged down in TCP-IP yet again.
Except this time something clicked. I suddenly _understood_ that the subnet mask simply delineated the addresses that were on the local network vs those that were not. It was the single most distinct feeling of illumination and understanding I had ever experienced.
I consider myself fortunate that I was given the opportunity to learn my craft and trade on the job. I have never had a mentor in IT, I have always had to grind it out myself. Remembering that feeling from that one day at the beginning has gotten me through a lot of the other sort of day we all have from time to time.
Shot in the dark -- could it have been TCP/IP Illustrated? That's a pretty well-known book from that era. I actually read it in 2014 to nail down the fundamentals of networking and it paid off handsomely (despite its age).
It eventually became necessary for me to start passing certification exams. As I was studying for the Windows NT 3.51 exam I bogged down in TCP-IP yet again.
Except this time something clicked. I suddenly _understood_ that the subnet mask simply delineated the addresses that were on the local network vs those that were not. It was the single most distinct feeling of illumination and understanding I had ever experienced.
I consider myself fortunate that I was given the opportunity to learn my craft and trade on the job. I have never had a mentor in IT, I have always had to grind it out myself. Remembering that feeling from that one day at the beginning has gotten me through a lot of the other sort of day we all have from time to time.