Airports are a strange place. People come to separate and some come to unite. Departures are mostly sad and arrivals are happy. For some there is happiness in sorrow and for others sorrow in happiness. I really love to be at the airport. You can see all these faces with anticipation. A beginning of a new chapter or the end of another.
There is an analogy with software development. Some people who have just begun to code and those who are reaching the end of it. Similar to departure and arrival. Inside software also there are many functions. Some waiting to be called, some never called and some being called more than necessary. If feeling was mathematical, lot of systems would work otherwise.
Take a loop which is exiting without reaching the final condition. Has the loop been useful? Maybe. Depends on what is under context. If we have coded an exception without taking into account the probability of it being invoked, the code would just become sterile. All parts of the code should get executed as per the standard variance. Else we are wasting our time and the system's too.
What does this all have to do with happiness and sadness? Well for one thing, a code that works is a reason of joy and that which doesn't makes you sad. Or more aptly put, makes you mad. The best code there is, is written by machines themselves. I'm referring to self modifying code like that of a polymorphic virus.
A good statement of requirements and a solid design will pave the way for good code to be written. Otherwise it will all fall like a stack of cards. And no airport or no getaway would make you feel happy. A job undone is a cause of concern. It will erode you from inside. And an unhappy face can be spotted by anyone. Hence the dictum 'Do it to the best of your ability and then feel good from within.'
Cheers
Guru30