Mark Gorman said that: " Not all dreamers are winners,but all winners are dreamers" so did you get it?
Unfortunately some people just waste their times wandering without taking action,they keep thinking of the build mansion they'll get when they become rich,but also unfortunately they still didn't get their first 100$ even!
Dreams are essential for any achievement in this life,the first one to invent an airplane didn't see another one and said to himself let us try to make it better,he just imagined it and worked till he made it come true.
I've read the book that is called "The power of your subconscious mind" and also "Think and Grow rich" and they talked much about the power of imagination,and how a man could achieve anything in this world when it's really important to him and when thinks about it enough.
But,as I said,there are people that only dream without taking actions,and this is the worst type of dreaming,because as long as you don't take actions you'll never get ahead even one step,and you're even wasting the time you're dreaming at.
The bottom line is If you take actions,then dream of all the great achievements you'll soon have and be proud of,if you don't take actions,don't even bother and dream,it's useless.
Hope this was helpful and I wish you the best in life