Our consultants are mostly concerned with teaching science and mathematics, claiming no expertise in the very different skill of teaching language. They have, however, learned several, which gives some insight into the process.
Some people put tremendous effort into extending and filling in their family trees. In the end, what purpose does it serve?
As we progress in school, the lessons get more difficult and complicated. Sometimes they’re difficult because we have to unlearn things.
What a photographer needs to do the job is sometimes far from obvious.
Proving that something doesn’t exist is hard, though it can be done. More often, scientists work out more and more restrictions on the characteristics something can have, until the idea has no place left to hide.