When we plan things, we do our best to make sure the plan is the best possible plan for whatever task it relates to. But, just because we’ve made a plan, doesn’t mean it’s actually the best plan for us. That’s why our plans don’t always turn out the way we expect, or want.
God has a plan for each of us, and is plan is always the best one for us. That’s why it’s always best to follow His plan for your life rather than your own plan.