A prospective PhD student visited Columbia and said in the common room "I love math." Herve Jacquet (one of the giants of the Langlands program) replied, "math will not love you back!" (He wasn't being discouraging, on the contrary, resetting expectations...)https://twitter.com/maanow/status/1081276599536893959 …
There's a profound difference between yearning for success and yearning for the unique satisfactions that come from intimate contact with mathematical beauty. The latter are available to anyone willing to learn what the great past masters have done, and how they have done it.