So it is 1:00 in the morning, and our youngest son wakes up screaming. At 18 months it isn't always clear what the problem is, but with a bit of attention he soon settles. Except the same thing happened an hour ago, though my wife got up then. And, almost exactly an hour later, he wakes again, and does his 'muuuuu-meeeeee' type noises in-between crying. Except I've woken up first, which sort of means it's my job to go to him, again... And at this point I remember that vital software principle: don't repeat youself (DRY). The tempting thing is to give him back his dummy, give him a cuddle, and within 2 minutes he could be back asleep - and in 3 so could I. This is the bet I am making: there's a small chance he'll sleep through the rest of the night. It's always possible. But far more likely is that he'll wake again, and I won't get much sleep at all tonight. Because if he woke 3 hours on the trot when he normally sleeps through without problem, there's probably a reason - maybe even a reason I could fix (bets on a dirty nappy?) But I'm tired, and tiredness makes me even more lazy than usual, and... I hope he settles and I go back to bed.
As in many areas of life, software developers continually have to make the choice between short-term ease against the risk of long-term disaster. If the disaster was certain, the choice would be clear, if not easy. But there is always the chance that it will never happen, and if the cost of averting that potential disaster is significant (e.g. lost business due to competition in time-to-market), it is no longer clear-cut. But each time the risk is seen and ignored, the likelihood of getting it done right decreases. If I get up at each hour from 1am till 5am to settle my son, am I really going to bother doing anything different at 6am?
So what are we to do? Recognise the need early, when the cost is least and the confidence of knowing that the potential disaster has already been averted can have the longest effect. Make the commitment early, not counting the short-term effort as a cost, but as a decision well-made.
I leave the quantitative analysis to Ian Fleming:
'Once is happenstance, Twice is coincidence, The third time is enemy action'
- Ian Fleming, Goldfinger
Enemy action must be countered with force of will, or we shall be defeated.