Final answer:
The "silly rubbish" likely refers to knowledge deemed impractical or frivolous by the speaker. This theme is present in literature where characters often contrast such learning with practical knowledge or dismiss it altogether.
Step-by-step explanation:
The "silly rubbish" that the speaker did not learn likely refers to impractical or frivolous knowledge, as opposed to useful, meaningful education or wisdom. This theme recurs in literature, where characters may dismiss certain types of knowledge or learning as irrelevant or unhelpful in the practical world. For example, in the provided extracts, characters express skepticism towards love and the pursuit of knowledge that seems disconnected from reality or practical application, such as nonsensical poetry or fantastical stories.