What does Charlie do when he realizes he will lose his intelligence?

In Progress
Report 13, when Charlie first knows definitively that he will lose his intelligence, he decides
he will write down his thoughts for as long as possible, saying it is one of his "few
pleasures." As his intellect and memory deteriorate, he records that he will fight as long
as possible to hold on to them.

Sadly, Charlie, as he knew he would, rapidly
falls back to his old state. Because he needs money, he asks for and gets back his job as a
janitor. To a small extent, he manages to hang on to some of his memories from being more
intelligent. For example, he remembers he shouldn't get upset if the people he used to know make
fun of him, because he now realizes they aren't as intelligent as he used to think they
were.