Your personal data is yours, not mine.
When visitors leave comments on the site, I see not just the comment, but also who it’s from and the IP address that they sent it from. I don’t use this information in any way (other than to weed out spam or bots), and I don’t save it anywhere except on the comment itself.
I will usually delete comments after a year, so your comment will remain in place, and in view, for that time. After that, it’s as if we were just “Ships that pass in the night, and speak each other in passing, / Only a signal shown and a distant voice in the darkness…” (That’s Longfellow, as if you didn’t know.)
Third-party stuff
If you leave a comment, it will be processed through a spam filter (in this case, Akismet) to shut out bots or spammers. Akismet is a company/service I have no control over, but — at least according to what they tell me — they don’t save any information from anybody who ISN’T a bot or a spammer.