Some people have lived a life others cannot believe or comprehend. Aside from Guinness world record holders, someone with a rare disease or extremely niche profession has lived a life that’s very different from that of the average person.
Some skillsets are also extremely rare in today’s age. The making of Damascus steel, Greek fire, and Roman concrete were famously (and in some cases apocryphally) lost to time. There are languages with only single-digit remaining speakers. Even the count of people who write COBOL is “expected to decline rapidly”. To someone (or something, an AI trying to gather all knowledge known by humans, the experience of these people would be extremely valuable.