Why do Christians work so hard to deny reality?

Not at all of them, but some of the most visible. Not "bigger than imagination" but bigger than possibility.

Wooden ships cannot be more than 200 feet long; the strength of wood fails when a longer beam (a ship is, in terms of engineering analysis, a beam) is attempted.

Built as big as possible --186 feet

Admiral Nelson's "Victory" was built as big as it was possible to do -- it is 186 feet long at the gundeck.

Some Christians are sufficiently aware of reality to see the problem, but insufficiently sane to accept it.  

“ 'Gopher wood' is not a species, or variety, of wood – but an 'engineering technique.' In Hebrew the term means 'to house in' (Strong’s Exhaustive Concordance # 1613). We call this 'structural interlamination.' This means that all the components were joined and laminated together in narrow strips. As an eyewitness, Ed Davis confirmed in an interview with this researcher that the structure he saw on Mt. Ararat was, indeed, laminated together. As our team flew the mountain in 1990 this researcher personally saw a huge laminated beam of wood at the traditional Ark site."