" Grothendieck's mathematical education changed radically by his arrival, in 1949, to the Cartan seminar hosted at the *Ecole Normale Superieure". As Grothendieck himself confessed(reference), he had not heard by then about topological spaces, groups, rings,modules, homology!!. The astounding capacity of Grothendieck is revealed in the giant mathematical leap achieved between his naive ignorance in 1949(in Paris) and his spectacular technical nous in 1953(in Nancy). At that year he finished his doctoral thesis about "nuclear spaces" and had become according to Schwartz in "the number one worldwide specialist" in the theory topological vector spaces.According to Dieudonne, Grothendieck was author by then of a life work "only comparable to Banach's"
Either you believe there is no such thing as mathematical talent and you and me are in the same caliber of Grothendieck or you have to accept there are people with inborn qualities to excel way above the average human in that area. Same for Kasparov in chess, Mozart in Music, Jordan in BB. Blank-slatism will be the death of western societies.
1. Make sure you understand the concepts
2. Mark what you dont know clearly
3. Write down what you know
4. Use 3 to find out 2.
Oh gee, thanks!
This is a more realistic approach.
1. Have a reasonable amount of mathematical talent
2. Study materials appropriate to your current level and mathematical maturity.
3. Work hard at it.
4. Ask for help when you are stuck
There.