You just have no idea.
Can you fly a jet?
Could you learn to fly a jet?
People claim that too is complicated...
Lets pull it a part. How many man hours are needed?
When did they start to plan 9/11????? 1995? They had more than enough time to either train people or bring in experienced hands.... and do whatever they wanted.... hypothetically speaking.
Maybe we should ask the all time waterboarding champ....