Hi Oman, welcome to the forum.
One of the reasons I tell people not to talk about their dreams is that there are so many pessimists about who think they know better.
The best thing is to avoid them as much as possible. If they "collar" you, get away as soon as you can and get into a positive atmosphere - maybe you have some good friends who do support you, or come here and read some posts, or read a good Law of Attraction book to or watch a DVD/listen to a CD to give yourself a boost. I can recommend anything by my friend Mike Dooley.
Stay positive and eventually you will attract more positive people, and the pessimists will eventually disappear from your life.
Thanks for a good question, I'm certain many people struggle with negative people.
Best wishes,
Edge.