Aha, I found it on Amazon finally, “your browsing history”. It’s absolutely buried at the bottom of the Amazon page for a given product, just above the footer.
What’s weird about this is that yes, I did browse those products, but quite a while ago, and most (but not all?) of the “browsed” products were purchased? So strange. The URL for it is
https://www.amazon.com/gp/history/ref=pd_pyml_rhf
Right, you can also view new topics per category, note that the New (x) count will change when you enter a category to reflect only the new topics in that category.