Assumption or Fact?
It is likely that you will encounter situations where there is value in considering whether your interpretation of an event or a proposed course is based on an assumption rather than a fact or facts. There is a potential problem with this! Your assumption may be wrong and/or difficult to verify, whereas a fact can be verified.
My suggestion is that you consider where are you making assumptions which have a significant effect on the outcomes you would like to achieve. What are the facts in these situations and how might these help you better than the assumptions your are making?