Both ways, you end up losing...
If you chase your dreams, (lets face it, they aren't gonna be realistic, they are called 'dreams' for a reason!) you are gonna be miserable in your reality because you can never truly be happy with what you have. If however, you do realize one of your dreams, it's reality and not what you want anymore...you already have another dream in your head!
If your dreams are subject to reality, you'll always be unhappy because you're always trying to imagine what reality should be like and so will spend all your waking hours always wishing things were the way you wanted them to be! Nothing ever is good enough the way it is!
So what do you choose?