Another factor we need to take into consideration is a growing thirst for knowledge. The Renaissance in Europe had led to the enormous expansion of learning in a variety of areas. The spirit of Renaissance humanism was infused with an intellectual curiosity that led to a much greater degree of engagement with the wider world. Just as the Renaissance had opened up new vistas of knowledge, so too did it open up large, hitherto unexplored parts of the world to scientific investigation. All of a sudden, the world became a much bigger place and the opportunities to chart, measure, and ultimately comprehend it, seemed endless.
We also shouldn't under-emphasize the role that a lust for glory and prestige played in the great Age of Exploration. Each nation saw the conquest of new worlds as greatly redounding to their benefit, allowing them to claim victory over their sworn enemies and rivals. Opportunities for territorial expansion were somewhat limited in Europe and would in any case lead to potentially long and bloody conflicts. Despite the enormous economic costs involved in exploration, the political risks were much less significant. Whichever country achieved success in their colonial ventures would enjoy considerable leverage in the fraught, competitive world of European power politics.