I have been taking classes in Econometrics this semester. The course has a section where we are told about how to use proxy variables for the outcome that can't be measured or observed quantitatively. For Ex: To measure ability to work, we might use a proxy variable 'education'. At first glance, it sounds weird. However, I realized that we tend to use proxy variables very often in daily life.
And more often we make mistakes in assigning proxy variables. Measuring success is no more a child's play, something successful at first sight may not be progressing at all, as the purpose of efforts was something more important which happens to be shadowed by the brightness of momentary success. We can be innocently choosing wrong proxies and be happy with the "pseudo success", unless someone points to the wrong proxy. Similarly, a proxy variable can be the cause of your sadness. You may be sad at the outcome of your work, while your efforts might have bore fruit.
A common example is current educational system, we tend to use examinations as proxy to measure the learning, which we all understand, is how much correct. I have seen people knowing a lot, and not able to show it all up in the exams and vice-versa.
So whenever, you feel progressive or frustrated of your efforts, give a thought about the "Success Metric". We often tend to forget about the real aim and by the time you realize it is too late. It is necessary to define the Metric of Success, before making efforts and amending the efforts towards the defined Success.
"Success means different to different people."
"Success is different for different scenario."