Software development can sometimes be very counterintuitive. For example, when people started building larger software systems halfway through the last century one of the things they discovered was that changing existing software is often far more difficult and error prone than building new software. Most developers rediscover this somewhere in their first year of being a professional developer. They start out with a new project and as time goes by changes start taking more and more time, this can be very hard to explain to a client and usually we don’t until we get completely stuck and tell the client we need to start from scratch. I think this practice has been responsible for most of the bad reputation software development has.