Some of the most underused data in Google Analytics is the records of what visitors did on the site.
In particular, I find the ‘User Explorer’ report fascinating. This tells you when individual users visited, where they came from, what pages they looked at and what else they did. The ‘Behaviour Flow’ report is also good, aggregating how users have flowed through the site, but there’s something fascinating about investigating individual visits.
Although unsurprisingly you can’t see anything that would identify the user, you can see information such as the device they were using, the source, etc.
It’s important not to take the small sample of visitors you might examine as representing a larger set, but the report can highlight unexpected behaviour. I noticed on one site recently that many people were jumping from one article directly to another, without going through any index page, and it made me realise the popularity of the ‘you may also want to read…’ links I’d provided.