Out of all the beings living on this third planet from the sun, humans boast of being at the top of the evolutionary hierarchy.
Acquiring knowledge and general understanding is not easy to get from self learning.
You know how things in movies always seem to have a happy ending, with a hero who always happens to be at the correct place at the right time! Out here, away from Hollywood, is a brutal, cruel world wherein humans are constantly surrounded by things and creatures that could potentially kill them.
Humans are inquisitive creatures, plus we appeal to our curiosity basically through learning and studying.