When did you hear this last? Today? Am sure you did. “You should read between the lines” is what you get to hear when you are being rejected or something is not working the way you want it to work. Is it really worth reading between the lines?
To understand the line reading between the lines, you will need to first understand why you are being rejected and then start understanding the person or the group you rejected you.
To understand why you are being rejected might not take long. For example, you applied for a position outside your skill set area and the company did not select you for the job, it is very simple to understand that you did not fit into the role. But, if you check marked all the requirements (and you fit into all) and then got rejected, then there is a little thinking which needs to be done. You will need to evaluate what went missing (either your resume did not exactly speak what you wish to communicate or you could not articulate your experience well enough). It is very important.
When I applied for my masters program, the first time my application got rejected. I did not understand why because I was meeting their criteria. The second time too, my application was rejected. This time, I walked in to the Institute to understand what is happening. The admissions office explained that they are categorizing applications based on Industry background (they do not mention this publicly). The first time they picked applicants with Finance background, the second time they were looking at Investment Banking background. I could have lost hope and left it there. But, knowing the situation helped me better understand as to why I am being rejected. Talking to the admissions office gave me clarity. So, the next time I applied I checked with them and then did.
Reading between the lines is important, but either you have to understand what is not connecting properly or the background of the person who is rejecting you. Only then it helps.