How to answer what has been the biggest disappointment in your life?

I have an upcoming interview and I am preparing some questions I have found on glassdoor from people that were interviewed by the company before. One of which was "describe a time you have been disappointed and how you dealt with it" and the other "what has been your greatest disappointment?"

I done a bit of searching on the internet, and this question came up with the person having saying to answer (if possible) about a personal disappointment of a early death of a parent. This is applicable to me, however I just do not feel it is appropriate for an interview. Or is it?

How would you answer this question? I do not even have any failed exams or anything like that to say. I know it's not definite they will ask this, but I just wish to prepare heavily.

what about first job search and not getting it as there were some better candidates. You can always say that you have tried to improve your cv/ cover letter gain new skills by volunteering/ helping friends amd just kept applying until you got the job