Well... I'll tell you... people who even enter that competition, know what they are getting themselves into... and are possibly true "Professionals". Now to non-professional pianists... this work may seem impossible. But some people make learning music of Liszt their life... And have built the habit of learning very difficult things at such a level... or have already played the piece before, and simply have to relearn it...not very simple actually!!
Take the "Olympics" for example... many competing from around the world... doing things no other human can do. Sprinting, jumping at heights no other can match...
Competitions like these are ment for the very best...