I have 3 theories why dreams do not come true and I would like to share it with you. :)
Theory Number 1. The Dream is not yours to live.
When I was a kid I wished I was a mermaid, or Darna (Philippines version of Wonder Woman). Imagine if that came true! If I had been a mermaid then I would have missed the wonderful life I have right now in the land (chuckle). If I had been Darna then I would have been so busy catching bad guys. Did you know that a crime happens in every minute? That means I will have no time to rest and no social life! This is a little bit of exaggeration but I'm sure you got my point. Some dreams are not meant for us. I'll just leave the Darna and mermaid thing to Marian Rivera, haha.
I also dreamt of becoming a doctor. But I took a different path. When dreams do not come true sometimes we feel crashed wondering why. We sometimes ask God "Why me Lord!?" But then, letting go and moving on comes into the big picture and then when we do let go and move we realize it was for the better.
Theory Number 2. The Dreamer Grew Up.
I got this theory from Bo Sanchez, hey I'm a fan. Bo said that there are dreams that do not come true simply because the dreamer grew up, physically and more importantly mentally speaking. You might have dreamed of a mansion or a classy car. Perhaps you dreamed of a Caribbean cruise or a tour in Europe. But now you realize, when you have the funds and resources to do so you no longer wish for these dreams to come true. Why? Because you've grown. You now have different priorities in life. You'll know that Theory Number 2 is for you if you know you CAN realize your dream but CHOOSES not to.
Bo used to dream of a robot, not just any robot but the Voltes V robot. When he was a kid he cannot afford to buy one, but now he's a lot more better of he chooses not to buy one even if he can afford it. Why? Because he believes that his money is more needed in God's work. The dreamer grew up.
Theory Number 3. The Dreamer Forgot the Dream
This happens for a lot of reasons. One reason I know and am sure of is because of the "dream stealers". Dream stealers are the following but not limited to: poverty, negative people who brainwash dreamers that dreams do not come true, tragic events, etc.
So what do you do with your dreams if you belong to Theory Number 3? Revive your dreams! Claim what's rightfully yours! People around you have no right to steal from you anything especially your dreams. Find that dream in your heart and live it.
So there, I hope somehow I've encourage or enlightened you in a way. :)
P.S. Comment below if you like to add Theory Number 4 or if you like to give your opinion about dreams. :)