We all are. Like rats in a box.
We don't actually need planets to live in outer space. Think about it: If we can build starships that take 1000 years to get anywere, we will have essentially built our own worlds. Don't need planets, it's a lame excuse for staying on this backwater mudhole of a planet.
No wonder. In 1950 there were 2.5 billion people on earth and in 2000 there were 6 billion. You ARE getting cramped.