There are various ways to make a plan, without a plan you have no end destination and are likely to fail.

You can gamble and concentrate on the dog, where you have no end destination as you are market dependent.

Or you can concentrate on the tail, where you can pencil in an end destination and can check you progress against the plan, every month and improve your plan as you journey along.

With investing you fail by the month not the year.

Dog or tail, or both. The choice is yours my friend.