It is easy to ignore facts if you do not like them, sometimes this can have major consequences. I recently heard two similar experiences of this.
We were driving along in dense fog trying to visit someone who lived out in the country. We had been there in the daylight and thought we knew the way. The conversation went a bit like the following
- It is along here on the right somewhere – there should be a big gate
- There’s a gate. Oh they must have painted it white since last time we were here
- The track is a bit rough, I thought it was better than this.
- Ah here’s another gate. They must have installed it since we were here last.
- Round the corner and here we – oh where’s the house gone?
Of course we we had taken the wrong side road. We had noticed that the facts didn’t match our picture and so we changed the facts. Instead of thinking “that gate is the wrong colour” we thought “they must have painted the gate”. Instead of “we were not expecting that gate” we thought “they must have installed a new gate”. It was “interesting” backing the car up the track to the main road in the dark.
I was trying to install a product and having problems. I had already experienced a few problems where the messages were a bit vague. I had another message which implied I had mis-specified something. I checked the 6 characters in a file and thought “The data is correct, the message must be wrong, I’ll ignore it”. I gave up for the day. Next day I looked at the problem, and found I had been editing the wrong file. The message was correct and I had wasted 3 hours.