Dealing with unfamiliar situations is challenging. While over time people do adjust, this adjustment happens only through experience which helps turn the unfamiliar into the familiar. Why do we let people gain this experience only while working? Why not let them experience new situations and gain confidence before they start their tasks or job?
Fear of the unknown is a common phenomenon in terminals where automation is implemented. Take a situation where automated horizontal equipment is moving in fenced-off areas. At times people must enter that area to work on equipment (e.g. breakdowns, lost transmission, slippery surfaces) for people new to automation, they must go out of their comfort zone to enter these work areas.
This fear or hesitation has to do with their unfamiliarity with automation. It can be difficult to present unfamiliar situations through traditional training. Experiencing the effect of external factors and the result of one's own behavior on a given process is more effective than reading and writing about what could happen. For example, if you have ever experienced the consequences of being careless during attaching twist locks to a container, the results effect will create a lasting memory.