Flight simulators allow you to do procedures that you couldn't ordinarily do in an aircraft, for the obvious reasons, so they are very valuable tools. There are very sophisticated simulators these days. We do a complete check-out on a new aircraft. In the actual aircraft you have passengers behind you, so that's how good they are.
That's for pilots who have been working in the industry for some time. Initially, you need to learn respect for the aircraft. You actually have to scare yourself a little bit. That's why you need to train in the real aircraft first and then gradually transition over to the simulators.