Pushing the limits

Great athletes have personal limits, just as everyone else does, but they don't accept their limits as stopping points. They push the edge of their capabilities and find every possible way to be faster, stronger, or more precise. In a similar way, engineers push the limits of materials and machinery to make devices smaller, cheaper, and more capable. Musicians challenge their physical limits in order to play ever more intricate and subtle pieces of music.

What are the limits and barriers that you've challenged and pushed against for years and years? What is one area where you've gone forward long after other people have given up?

This week's theme is barriers and limits.