"Nya" is actually the definite form in this sentence. The definite form is usually the same as the plural form.
The definite form is used when a noun is definite, like in "Den nya idén" - "The new idea"
It's also used with possesive pronouns like "Min/Din/Vår/Er/Sin nya idé"
It's only silly because of how most people tend to think. Re-evaluating one's own thoughts is a core aspect of both philosophy and a number of religions.
It is, however, much more likely in English that you would hear something like this using 'contemplated', 'considered', or even 'evaluated' instead of 'thought of' or 'thought about'.