For a Product Manager it is important to understand the underlying needs of customers rather than what they express in superficial statements:
On the one hand, it is not the job of the customer to think of solutions to problems, they might not even be able to imagine what is possible, even more so in today's fast-paced world of technology-driven innovations. On the other hand, even when they suggest a solution, in most cases this proposal will come from their current context, from their experience with the status quo.
To overcome that situation, it is essential to drill deeper, to keep asking questions in order to understand the actual root cause. Asking the right questions can make the difference between failure and success, between something that appears to be obvious based on status quo and something that truly helps to serve the needs of customers.
However, the very first response given by customers, e.g. during a user interview, in most cases will not dig deep enough. To help in these situations, the 5 Whys technique can help:
5 Whys assumes that there is a cause-effect relationship and the root cause of a problem can be revealed in an iterative way by repeating the question "Why". Each answer will then form the basis for the next question, and considering 5 as a somewhat arbitrary, magical number, the idea is that after 5 such iterations a problem will become apparent that might have a variety of different solution options — which would not have been obvious from the initial problem statement. When this isn't linear but different alternating factors are to be considered, then Ishikawa or fishbone diagrams are often applied.