How to interpret a postdoc rejection letter? Few days ago I appeared in a postdoc interview. The PI was very much impressed with my resume and the interview went very well. The PI asked me when do you want to join. The next day he asked recommendation letters from two of my references (I am sure that they will give me a very good recommendation). After 2 weeks I got the rejection letter. How to interpret this rejection (he told me that the position is filled by some other candidate). This will be useful for my future postdoc endeavors.

I politely asked him the reason. He did not reply. 

Thanks in advance. Sorry if this question is inappropriate.
There isn’t anything to interpret. The only conclusion you can draw is that there was another candidate whom the professor thought would be a better fit for the position, for an unspecified reason.

Our minds have a psychological tendency to want to fill in a lack of information with speculation and beliefs. The added information you have in this case is literally zero, so you must resist the urge to “interpret”; it is futile and serves no useful purpose.

Good luck with the job search!