Ideas should be free, implementations shouldn't. As long as I'm not using the actual implementation of whatever I created for my employer, I should be free to u

Ideas should be free, implementations shouldn't. As long as I'm not using the actual implementation of whatever I created for my employer, I should be free to use the idea of what I created for any otherwise legal purpose. After all, isn't everything 90% perspiration? Now we just need to define exactly what constitutes implementation.