It is part of the artistic process to make what is very difficult appear to be very simple. This tempts people to say "I could have done that" when in reality they can't. To take an example from music, it is much harder to correctly play a piece like the Bach Prelude in C major from the Well Tempered Clavicord or the Sarabande from the Goldberg variations than some fast and loud piece. The slightest mistake will be glaringly obvious with the Bach.
Not a fair example... one mistake while playing Bach and your fingers end up tangled together, lol.