[scott_s]

I agree with everything above, but I would like to sum it up in my own words: we (as a species) were so new at writing software, that we had no idea of its inherent complexities. Programming was an after-thought for those that designed the first computers.

[Zaak]

As soon as we started programming, we found to our surprise that it wasn't as easy to get programs right as we had thought. Debugging had to be discovered. I can remember the exact instant when I realized that a large part of my life from then on was going to be spent in finding mistakes in my own programs.

— Maurice Wilkes