I actually live with the believe that all my assumptions, and everbody elses assumptions are wrong. They are just ends to a means. If you got good assumptions, they will bring you want you want. If you got bad ones, you get the opposite. But there is no inherent correct of wrong assumption. It's all utilitarian.
It is all part of the story we tell ourselves in various ways to make sense of our world. If it helps us move, good.