This question sounds general; however, the interviewer is still looking for a reply that relates to your career, or education. This question is not the time to tell them that leaving your wife was the hardest choice you've ever had to make! Leave that conversation over beers with friends.
Use an example such as changing majors in university, quitting a job, leaving the family business, relocating to a new city for better opportunities, or even starting your own business. Be sure to highlight how things have worked out for you since making this challenging decision.
"The most difficult decision that I have had to make was changing my major from accounting to international business. I am so happy that I chose this path because I have built a very lucrative career; however, my family was not supportive of the decision because both of my parents are accountants and they wanted the same for me."
"The biggest decision I have ever made was to quit my last job and move to Denver. I have a lot of friends here, which made a choice a bit easier, but leaving my hometown to explore other opportunities was certainly a major decision in my life. I have zero regrets as I love this city. It's my home for good!"
"I was accepted into two major Universities at my time of application and would say that was a tough choice. I weighed my pros and cons, including location, reputation, my major, past alumni, and more. I am a bit of a nerd, so I made an Excel spreadsheet and pie chart to help me make the decision. Thankfully, I made the right choice in the end!"
"Choosing my major was probably one of the toughest career decisions I have made. I was on the fence between B2B Marketing and Consumer Behavior. As you know, I chose B2B Marketing, for which I am thankful that I did. B2B strategies are changing fast, and I love to learn new ways to position my clients in this incredibly competitive marketplace."
"Last year I chose to stop working for my parents, at their print shop. I wanted a job more fashion oriented, and a bit distanced from family, as you may understand. I helped them to find a replacement before leaving. It was a tough conversation because I wanted to tell them about my dreams without offending them at the same time. This decision has improved our relationship, and I am thrilled that I chose to put myself and career desires first."
"The most difficult decision I have had to make was to let go of the business I started and get back into the regular workforce. The business did well, but my partner and I had differing ideas about where to take the company. He offered to buy me out, and I accepted. I love being in software sales now and never look back on the choice I made, but it was one of the most challenging of my career."
"Initially, I started training to be a High School teacher and decided to switch to an Elementary focus. I knew there were job opportunities for male teachers in Elementary and my focus was to make myself more employable. I am still pleased with the decision that I made."
"I am confident and prepared to face challenging situations that require me to be firm in my decision-making."
"Yes, I do consider myself a strong decision maker. As a Radiologist, I face incredibly challenging choices every day. I am skilled in this aspect and able to think critically, rather than emotionally, when it comes to patient diagnosis and other difficult topics."
"When someone comes into my office requesting information regarding a patient, I always review the patient's chart first to verify whether or not the patient has given permission to release information. If the person requesting information is on the signed release of information, I go over what information they have permission to obtain and ask them to sign the appropriate forms to acknowledge receipt. If the requesting person is not on the patient's release of information, I advise them that, according to privacy regulations, I am unable to release information without the patient's expressed written consent."
"The school I worked for was making budget cuts and I, along with the principal and board, had to decide which of two teachers to lay off. This choice was tough as they were professionally capable and I had good personal relationships with them. I made a pros and cons list, talked to their students and their students' parents, and discussed options with each of them extensively before making a decision. In the end, I wrote a stellar recommendation for the teacher we let go, and he got into an amazing school. I think it's essential to go the extra mile when making difficult decisions like this."