"Yes, in an environment that can sustain life, heading to a place that might have something you want."
Early navigators didn't know that. Ridden by superstitions, doubts, inaccuracies. I've recently visited a -- they say -- size-accurate replica of Pedro Alvares Cabral's caravel. Official history say that he was the first to arrive in Brazil in 1500 A.D., a few years after Columbus's trip in 1492. It's about 100 ft in length (30 meters), and held about 150 men. Columbus's ship were about the same size. In that time, there was no GPS, no radio, no refrigerator, not even an engine. Maps were populated with "here be dragons", "end of the world" and such - today we know it - nonsense.
Today we know exactly what waits for us in Mars: cold; radiation; lack of atmosphere pressure; lack of breathable air; scant natural resources. We know exactly how to go there, and exactly how long it takes. So, is taking humans to Mars really as daunting a task as taking humans from Europe/Africa to the lands on the East?