The only key to success (or precisely optimised life) is precision. It doesn’t matter with how much hardwork you achieved that precision. If you never achieved that precision you’re not living optimally. In field of algorithms analysis, it is known as tightly bounding, running time of algorithm. In troubleshooting field, it means accurately identifying problems. Optimization of code depends on precise definition of what is the objective of code. Different words in different fields but the same meaning.