Why would a pioneer traveler record events in a journal?

I would take notes just for historical reasons if that makes sense, and you can also go back and reminisce, or remember something you learned on your travels

With historical events, pioneers probably wanted evidence of the true story of what was going on, that way it would be there in writing for next generations. It’s also so that we get a different point of view from a person who was actually there. Like I wrote about coronavirus when it first started the pandemic and now so can look back on that and see my point of view from then and now.