Because achieving it generally means fulfilling a dream you’ve had since childhood. But if reality has changed your dream’s rules, you should choose a new one and abandon the old one. Making a practical choice is ideal in the end. There are many factors that might make it hard to decide to abandon a Ph.D. program:

• There’s the sunk cost fallacy to consider. Some may feel that “the Ph.D. has already cost me this much in terms of time, mental agony, and wasted chances.” Everything will be for nothing if I don’t complete it. Whether you get your Ph.D. or not, you still have to pay the bills. Logic dictates that you consider how much time, stress, and potential gains earning a Ph.D. will set you back in the long run. Is it worth it to go through all that trouble to acquire a Ph.D.?
• Anxiety over how a Ph.D. program’s completion delay or failure could affect future employment options. How competitive will you be for graduate employment after spending years attempting a Ph.D. with nothing to show? Suppose you take a step back and look at it objectively. In that case, you’ll likely find that you still have something to show for your Ph.D. If you were a strong enough candidate to get into a reputable Ph.D. school, you probably have solid credentials. You can still get good positions outside of academia.
• Identity. Being a brilliant person who will acquire a Ph.D. is often central to the identity of Ph.D. aspirants. For no reason, many people fear that quitting would forever define them as a failure.
• Ego. Pride is fatal. One’s intellect is a significant element of one’s sense of self-worth, and if you’ve been accepted into a Ph.D. program, you presumably agree. To give up on a Ph.D. is like giving up on yourself altogether.

It is not only about Ph.D. In the same way, it is tough to give up anything; giving up senior high school, university, or a master’s degree is also tricky. If you consider losing or falling short synonymous with giving up, you’ll see that PhDs are not alone in the competition.

It just takes a few clicks and seconds for anybody to leave. The only thing that matters is that you fight for what you want and overcome the obstacles in your way: this is how life works. According to Victor Frankl, it is through adversity that one discovers one’s life’s purpose; pleasure and sadness are only states of consciousness. In Ernest Hemingway’s, The Old Man and the Sea: “Man can be defeated, but not destroyed.”

Life is defined by adventure, pain, anguish, triumph, difficulties, and sacrifice. All the luxuries, riches, and safety we enjoy now result from millions of forebears who refused to accept “defeat, failure.” It’s so ingrained in our culture that it’s tough to experience the bitter taste of defeat, and giving up on a Ph.D. is no different.