I'm in the same boat as you!! My DD will turn 4 a week after we get back. My mom is 72. I figured this would be a good year to go since they both travel at about the same speed!
My mom is excited to go because like the rest of us on this trip it will be her first time there but she's just not a planner and she's scared of flying so her fear of that keeps her from getting excited, she sees my countdown as some doomsday countdown.

She'll be great once we get there!
My DD is def becoming quite the planner though. We were in the car the other day and she was really quiet so I asked her what she was thinking about and she said, "Oh I was just thinking about Disney." So I asked her what about it? And she said, "The restaurants. I will eat at that one with the TV's (50's Primetime) I think it will be okay." She has a lot of opinions on what she will and won't do but it does make planning easier!
So you be as excited as you want to be and we'll be just as excited along with you!!!