You know, it's really all Disney's fault. Use to be all you had to do was drive to Orlando, find a room, and head to the parks. If you wanted to eat somewhere special, you'd make the ressie at the park. But restaurants were rarely more than half full, so it wasn't necessary. So dining plans were born, and with them ADRs.Also the drowds grew. So we started planning our dining, and hand in hand with that, what park on what day. Then we just got nuts about planning. Gotta get to Dumbo first thing, then run to Space Mountain. Then came fastpasses, and we needed a strategy for them. So, after Dumbed, go by Peter Pan and get a fp, then head to whicheverland and get in line for one ride, then, when your window is open, get another fp. It sort of snowballed. Now if you don't have some huge book with details of the day, you don't feel ready.
Now I try to have my ADRs, cause I loves my food a little too much. I usually don't have an ADR the last day and we play that day by ear. I try to know where I'm heading when we get in the park, and I like to have an exit strategy, but if I wander from land to land the rest of the day, I'll find something I want to do, just like back when.