I can tell because I've crashed about five times in each of the training missions. I'm getting the hang of dealing with the radial precession of a rotary engine, so I've made a couple of really good take-offs. Far more often, I wheel madly around the runway, desperately overcompensating to the turns my crate is making. It's not pretty.
The difference between a flight sim and a flight game is that the sim gives you the plane, warts and all. With modern computer speed and detailed programming, the particular quirks of the aircraft (like shedding its wings in a steep dive) are now being accurately simulated. The flight sim is therefore much more difficult to master, but this also makes it more rewarding in the long run. But right now, I'm at the bottom of the learning curve... and that means a lot of crashing.