I feel like a lot has been lost since the days when I was in my parents garage making TCP/IP games to run over dialup.
1. Binary was the only choice
2. You had to assume packets would get delayed (sometimes 10+ seconds) thus you had to do some fun stuff like try to use math to predict where the player would be based on what they were doing last time you got an update.
3. You had very little RAM to work with so growing memory would be immediately noticeable.
#2 was the primary reason in old game you used to see other players walking into a wall for 20 seconds before jumping half way across the map. Darn n00bs who couldn't afford 56k (joking).
I fondly remember the first time I played a multi-player online game I actually had to dial into my friend's modem over POTS. I then spent the next two months reading telephony documentation trying to figure out how to use the modem to do things like that myself.
</nostalgia>