I don't think many people are memorising a bunch of wildly different IPv4 addresses either.
At best, I remember the prefix of my private network, and a handful of single-number suffixes of important hosts (i.e. my LAN is 192.168.1.x, and I remember that .100 is my local file server...)
At best, I remember the prefix of my private network, and a handful of single-number suffixes of important hosts (i.e. my LAN is 192.168.1.x, and I remember that .100 is my local file server...)