Question: Why is building computer models on very big computers your favourit thing

David Ingram answered on 15 Jun 2011:

Its fun and quite creative. Although this applies to building models on small computers as well. On big computers you get the challenge of using thousands of processors simultaneously in an efficient way.

I think its the scientific computing version of driving high performance cars or climbing big mountains. There is the satisfaction of your module using 1 million CPU hours to run!