I left my Big Law job in March 2017. It was an extremely difficult decision, and I can empathize with people who want to quit a job but are held back for various reasons.
Having said that, I think it's difficult to quit a job because of one simple idea: fear of the unknown.
It’s too easy to stay in a job we don’t truly enjoy, even if we desperately want to try something else. There’s safety in our current situation. We build routines and become comfortable in our day-to-day lives. It’s scary to venture out and try something new.
Change is often difficult to accept because the future is often uncertain. This fear of the unknown rises to the surface when we consider leaving a job. Further, loss aversion comes into play. It’s a real thing: some studies have shown that humans feel losses twice as powerfully as gains.
Granted, these fears may be well-founded, whether they are financial or something else. But often, these fears are created in our own minds. We may fear what our colleagues think of our decision. We may fear what our parents or friends will think if we leave a well-paying, prestigious job. We may fear failure in our new gig (or, in some cases, fear success).
When leaving my job, I definitely questioned my motives, but ultimately knew that it was the right time to take a risk. At some point, you just have to make a decision, notwithstanding your fears of what could happen.
I think this attitude can be encapsulated in one quote: feel the fear and do it anyway.