how often reason is used to justify pain
As long as reason is being used to justify pain so that greater pleasure can be obtained then tat would presumably be correct reasoning.
I get the feeling that our error is often not so much "listening to reason" vs "listening to the feeling of pleasure" so much as it is that we lose sight of the fact that the ultimate goal of reasoning is to achieve pleasure (even if temporarily through pursuit of pain).
Definitely it's hard to know how to succeed in the face of many types of challenges and that kind of practical learning is required in addition to the raw philosophy.