It was a hard slog for us (mostly my wife since I'm at work most of their waking hours). Eventually it just clicked, first the 1s, eventually the 2s. My wife's family (mom and 3 sisters in law) all said "they'll get it when they're ready," I guess my MIL thought my oldest brother in law would be going to kindergarten in diapers. So it must be an age old fight
Discussion
Looks like it won't be easy. We're making progress each day, but I imagine it's a long way off before it fully clicks in.