I guess you are talking about the problem of induction. To this, the canonical LW answer is Where Recursive Justification Hits the Bottom (whether it's convincing to you is for you to decide).
I'm not sure if I'm understanding your question correctly; are you asking whether you're obligated to act in accordance with what worked in the past for you? One response could be that if you always follow what worked in the past, then you'd be akin to the recluse, constantly exploiting and never exploring. This means you could miss out on great opportunities that are not part of your past experience.
If the only reason to use past experience (memories/knowledge) for making decisions as to what to do, is because that experience shows me it worked most of the time and that it's the only thing I have for that, then does it really mean I have to use it for making decisions?
And if yes, is there any other way of saying this, other than "I have to trust past experience because past experience tells me that"?