OK, to clarify - happiness ought to be the thing you are walking on, not where you are going to. Does that help?
Let's try and think about this reasonably objectively. Pilots are paid to spend most of their time sitting looking out of the window at scenery, whilst doing something that about 40% of boys, 30% of adult men and 20% of females think is one of the most exciting things in the world. Flying aeroplanes or helicopters, that is. There are legal limits on the amount of time they can work - as indeed there ought to be. They have hotel bills paid for them, food provided - free or subsidised, and allowances paid. In many cases, they have travel benefits which allows them to get cheaply to parts of the world much of the population only dreams of. Their training, whilst tedious, is structured and professional. They don't get Seasonal Affective Disorder.
So why shouldn't they be happy?!