Doubt is the vestibule through which all must pass before they can enter into the temple of wisdom.

Uncertainty is placed as a stage to move through rather than a failure to arrive. Nobody understands anything properly without first losing confidence in the easy version, and that loss is uncomfortable enough that many people turn back at precisely the point where the learning would have begun. Doubt is a room you stand in, not somewhere to live.

If you have recently lost your certainty about something that mattered, that is not necessarily going backwards. Stay with the questions long enough to see what survives them. Whatever you rebuild afterwards tends to be less tidy and considerably more reliable than what you had before.