Happy accident, spontaneity, lucky chance, even creativity… these are less likely to happen if everything is planned down to the last detail.
Planning is good, especially if you like things to be organised, but it’s also handy to know when not to plan, and how to make the most of not having a plan.
At the very least, nothing can go wrong when there’s no plan. At best you might find new benefit and enjoyment in going with the flow.
If you are not comfortable with the idea, or if it sounds irresponsible not to plan, how about a planning session to plan for the times when there’s no plan, or when the existing plan isn’t working?