@burnout426 I appreciate the reply, so thank you first of all.
That being said, nothing you've said has made a difference to my experience. Opera definitely did not start pulling up my bookmarks as search suggestions before I posted in this forum. It happened one day without there being any update that I was notified of (when I turned my laptop on today and opened Opera it notified me of an update that has just been installed and outlined the updated features, so I'm assuming when an update is released a user is notified in some way).
I have no idea why anyone would think adding bookmarks into search suggestions would be a good idea. When a user has bookmarked a page, they already know how to quickly access that page - that's the sole purpose of bookmarks! Adding them to search suggestions (as the first suggestions, especially!) is putting a hat on a hat. It's useless and irritating. There should definitely be a configuration for it. It clutters up almost every search I do as I have a lot of bookmarks, so I can't type anything in the search without pulling up multiple bookmarks before anything else.
I'd already tried emptying the trash from the bookmarks and the deleted bookmark still gets pulled up in suggestions. At this point I think I might have to reinstall Opera to try and get rid of that as I don't know where the errant file is it's pulling the info from and I haven't got the patience to search for it any more than I already have.
Overall, this is a hugely frustrating, disappointing experience as this feature has been forced on me with no option to turn it off. Thanks a lot, Opera.