http://www-history.mcs.st-and.ac.uk/Biographies/Poincare.htm...
http://www-history.mcs.st-and.ac.uk/Biographies/Peirce_Charl...
http://www-history.mcs.st-and.ac.uk/Biographies/Smale.html
Also, please check out some of the giants on that site and wikipedia: Gauss, Laplace, Euler. Why were they interested in what they were? What techniques did they develop? A very crucial question that very few ever ask: Would they have done much differently had they had access to a computer? (Of course).
Focusing on proofs to learn math is very perverse. A proof in a textbook is a proof that has been refined an almost ludicrous number of times. Definitions and axioms have even been optimized for the sake of elegance of said proofs. Don't get me wrong, a connoisseur appreciates what has been done. However, removed from the problem that motivated this way of thinking, mathematical techniques can often confuse more than enlighten.
What would you like to learn exactly?