I think it's two things causing us not to dream anymore : judgement and fear. People have become too afraid to be judged, to pursue their dreams. Me personally, i'd like to build a spacecraft and an iron man suit. Most of you will tell me i wont succeed. Do I care? No. Thats why i started studying physics ; im pursuing my dreams! Many of my friends are just happy when they eat, live and die. The other thing component is fear. People rather stay in their comfortable homes than go out. They dont go out to bars meeting strangers. I think " may you live in interesting times" is a chinese curse . Concluding, I think people are too scared of either whats to come, and of being judged. Take away these elements, and people will dream again. One thing I think may catalyze this is a common goal. People on the moon, mars or beyond? Everyone will share a sense of connectedness, which will be very benefiting to mankind as a whole.