Honestly, the question is incomplete. I'm probably going to get boo-ed of the stage by the asker and everyone else here....also @musing

It should be "Do you think you can plan your life and execute that plan successfully?"

if the questions was just, "Do you really think that you can plan your life?". Then the evident and final answer is YES

But can someone, a family, an clandestine organization, a country socially engineer and plan out someone's whole life and make sure they follow the bulk of that plan, the answer is a statistical dismal failure of a no....maybe 1 in million at best.

Can someone plan out their education, to some degree and with some fore-knowledge, yes.

Can someone plan out the exposure and education for their children, yes.

Can education ensure a successful life.....not exactly, but i will tremendously increase the probability, (like alot), depending on the quality and the content (and context - think teaching your kid programming in the late 1990s and early 2000s) of that education.

Can you plan a whole life and follow that plan, probably not, between biology, nature, nurture, conflicts, chaos, and circumstances, and financial barriers of entry for most, it would not be wise to rigidly plan a life.

Having said that, it's import to plan an acquisition of knowledge, getting and know more, timely knowledge in particular, is the best insurance and the one of the best strategy to have a well lived....albeit partially planned life.

AKA. Invest in yourself, plan for the worst, plan for best, but expect randomness and a little luck.