I received a Google security warning about my logins and passwords. I was surprised at how much Google seems to know about my accounts. I have many logins that are not important and I often use the same password on these. Google seems to know all of them, accounts and passwords. It also knows the passwords on some other accounts that are important, like my main email account and Geekzone. I do not have 2FA as I do not have a phone (my choice). 

I rarely use Google for anything and most of the time I have it switched off in my browser. I have a Gmail account, but I only use that as occasional backup. I mostly use other search engines, though occasionally I use Google. My browser is not Chrome, but it is Chrome-based (Comodo Dragon). My OS of choice is Windows.

I can't recall for certain if I have used the same browsers to access all the web sites that Google seems to know my logins for. There are some in the list that I don't even recognise, others that I haven't visited for years. I know Google and privacy do not belong in the same sentence, but I am alarmed at just how much Google seems to know. If they have all this information, how much is accessible to others? 

Admittedly, I tend to be somewhat lax about security, though not completely oblivious. I don't want to be blasted for this, but I would like to have more insight into just how Google obtains all this data. A long time ago, in the days of MS DOS, I used to be something of a hacker, and I am not completely ignorant of these things, but what knowledge I do have is very out of date. I am now elderly and my computer usage is pretty simple, just email, some news and streaming sites, and Geekzone. I don't wander the web much and I avoid shady sites. I like to keep things as simple as possible and I don't want to have to navigate all kinds of security questions or captchas or whatever every time I click on something. 

So how does Google know all this, and should I be concerned that it does? As far as I can determine, it seems to know every account and password I have. I am not just talking about passwords that have been obtained from compromised databases, but also ones that haven't. Even my Geekzone password it knows, and that, with a few others, is something I have been very careful with. I would appreciate any insights anyone can offer on this.

Edit: On reflection, the above may not be clear enough. I do use the Chrome password manager to save some passwords, but I am seeing a lot on the Google account that I have never saved, and that I probably didn't access with the Google account turned on. I am wondering where that information comes from.