What is the right time to decide what to do in the future?
I think there is no right time to decide, because in your childhood you want to become something, as you grow your field of interest changes. Most importantly your wish doesn’t remain the same life time, at every stage of life it will differ. When you explore many fields your interest will keep on changing.
Whenever you decide what you want to become at that point only start preparing for that and that is the right time you can say. Off course, there is a limitation for this. If you are a hard worker it will take a long time, but if you are a smart worker you can finish the same task in optimal time.
Anytime actually, you can decide now, right now what you want to do in future, but the wish to follow up that decision is up to you.
Life changing decisions come from the most humbling moments in life, like when you are taking a dip or having a bath.
If you mean matters such as education or decisions that may or may not shape your future, then I should say anytime that is well beforehand and can be easily planned.
You can go through much of life deliberately avoiding hard decisions. But sometimes you have no choice: the situation forces you to make a decision. Consider an example from the sport of mountain climbing.
Sooner or later, every mountain climber faces a dreaded section of slick granite that offers no ledges or cracks to grasp. When you climb such a wall, you can abandon the climb. Or, you can risk a move like “the pendulum”. The pendulum works the way it sounds: as high above you as you can reach, you fasten a loop with a metal nut and slide the rope through the loop. Then you climb down a few feet, dangle on the rope’s end, and try to swing across the sheer section. It takes nerve!
The author of Hebrews wrote to people who faced just a climactic, can’t-turn-back decision. It involved not a mountain climb, but their entire future.
My motto is always: Whatever makes you feel bad, leave it. Whatever makes you smile, keep it. Have fun living it too. Follow your passion.