People always dismiss this as FUD but it's been happening to me more than ever. I know in many cases it is more likely that firms are acquiring purchase histories and location data but that doesn't explain other incidents.

For example, last week I was complaining to my spouse about shoulder pain and how I was afraid I may need another surgery. YouTube has suddenly starting flooding my feed with videos about "shoulder exercises to avoid surgery." I hadn't searched any of those terms, purchased anything or visited an orthopedic, so I don't know what else could possibly explain it.

The alternative explanation is that your spouse searched up something related to your situation.

That’s the next possibility to eliminate.

I am positive I get ads based on the interests of other people the wifi where I live.

It could have been something as simple as lingering on some kind of content related to physical therapy on a social media feed before scrolling past it, or maybe your wife googled it and it got correlated via network?