Philippe Petit, A French wire walker calling himself an artist was stunned by the sheer size of the NY World Trade Center which in 1973 was under construction. Then he defined his dream as conducting the illegal wire-walk and walking from the one tower to another and start gathering "accomplice" to make it happen. The film is based on a true story (I don't know if it's cool to write out "true story" in film poster though).

The film itself is well written with a beautiful and organized story-line, but the insight I got from watching this movie was about how one achieves the dream: (1) you have to have a great dream such that the others would say "that's crazy, so I'll join that too" and (2) you have to prepare to achieve it very (x100) well (Petit's preparation for the walk was somewhat paranoiac). 

Real photos:

http://www.telegraph.co.uk/film/the-walk/philippe_petit_world_trade_center/