Why is it important to learn about figures from the past who have been left out of history books?

Every semester in a history class, you are given a 500 page textbook. You don't like history since there's so many people to memorize, but you learn anyway. All the way back from when history started to the common times now, there had been so many people that lived during those ages. Some shined out more than others, which made it onto history books but there were still people worth noting that didn't make it in. While a man might've been less important than Thomas Jefferson, he could've created a cure for a deadly disease back then where he was miscredited or ignored due to lack of coverage. The sad truth is, history textbooks are limited. We cannot fit every influential people, and we focus on the most important but the ones not on the books may sometimes lead a stronger legacy than the ones mentioned in books.

the narrator is a first person, participant one, who describes in the simple past tense important and difficult events in his earlier life. he also provides temporal markers as the month (january) and the time (12: 30 pm). finally the account of his experience is very detailed, to the extent that a participant narrator would talk the same way about his experiences. a good example of such detail is the mention of the “bovril ration” which historically was a native american food adopted by european explorers in arctic and antarctic regions due to its high level of calories.

what are the answers?