So here is your scenario
You go to sleep one night and then wake up finding you went back in time and you are now 3 at the same point in time you were originally 3. Everything in your life from 3 till now had been a dream however all the knowledge you learned and all the people you met are real and accurate, in fact if you do everything just like you did in the dream everything will happen exactly the same way. But that does not mean you can't change anything.
You may do anything you want and change whatever you like the only rule is you cannot let anyone (or the public) know you are practically from the future (or have experienced it) or do anything that would make the public (or a large amount of people) suspect/thing you are an x year old in a 3 year olds body. What happens if you break the rules? You get locked upfirever, you die, you become 3 again and start over, just something that is basically game over for super genius 3 year old.
So what would you do, what would you change, and how effectively would you use your knowledge
without breaking those rules (you can let a person or two know but remember the word can't get out to public knowledge) just answer below what you would do.