You just need to solve more computationally intensive problems. There are plenty of simulations and mathematical graphics you can make which take hours of rendering time on a fast modern machine, where optimizing the inner loops can have a big impact.
Constraints make a lot of creative endeavors interesting. I have no idea why Lego modeling is so compelling when you can just print miniatures, but for me looking at people's work is like crack.
You're just solving the wrong problems then. Try rendering the whole Earth at sub-cm resolution or something. There are so many things we can't do right now because we're too constrained...
Chuck, people have been saying that since punch-card days.
And here I am, cutting out strings from my program to make it fit under the 1MB barrier for my bootloader-to-SRAM to be happy :)