Todd is an expert in fixing computers. One of his new employees asks how he knew where the problem was. Todd was surprised that he couldn't explain it, that he "just knew." Should Todd be concerned about his decreasing mental abilities?

Todd shouldn't be concerned about his decreasing mental abilities, because it is not uncommon for experts to have trouble explaining their process to others.

Explanation:

An expert is someone who has deep knowledge concerning a certain field or area. Even though we tend to expect them to be great at explaining what they know, the opposite is what we commonly find. Experts find it hard to convey what they know so well because they also tend to do something - they forget what it is like to not know. Therefore, they can omit details that, for them, are pretty obvious, but which are not part of a regular person's repertoire. Another possibility is that they no longer follow a logical process to find a solution or reach a conclusion. They are so used to doing something that they "just know". Then, when asked to explain, they are lost for words.