Really and truly you cannot plan for anything.
To 'plan' is futile, and a total waste of time.
Imagine all the things you could be doing instead of planning.
If you plan for things, and they don't happen, you just feel let down, don't you.
If you plan for things, and they don't turn out the way you expected, you feel let down.
Rarely do things we plan for actually happen the way we plan them, or live up to our expectations, no matter how high or low they are.
And even when you are prepared for something, and there is a loose plan in effect, for said event, still, everything can end up, up in the air.