If you turn your brain off its ok. But you think about it for only a second and it makes no sense at all. How does a pilot from ww1 know how to fly a modern plane? Why was Diana such a dick in this movie and why was she basically squatting in this guys apartment, why was she ok with Steve taking over his body? Why does Barbara get a second wish? The whole thing is full of plot holes and comes crashing down when you think about it for more than 5 seconds.