Quixotic: 1) of or like Don Quixote; 2) extravagently chivalrous or romantically idealistic; visionary; impractical or impracticable.
(found in A Man Who Was Thursday)
Megalomania: 1) a mental disorder characterized by delusions of grandeur, wealth, power, etc. 2) a passion for or for doing big things; 3) a tendency to exaggerate
(found in Mere Christianity)