I guess this is simply a time to learn about what happens when you make comments in public. This, by the way, is why politicians never say anything interesting. There's no way to go back and change or delete it.
If you regret what you said, then say so. If you've changed your mind, then say so. the audience here is generally accepting of the fact that people change their mind. If done appropriately, it's a sign of strength.
Owning up to it even more so.
I like to go over my Reddit posts regularly to remove (or edit to neutralise) comments which haven't drawn much interest from Redditors and aren't particularly important, but which do give an extra titbit of info that could be used to identify me and isn't available in my other comments.
I enjoy the anonymity that lets me express myself more freely without having to worry about colleagues' judgements and retribution (for example).
I thought this site might operate like Reddit, where comments can be deleted and edited.
I remind you that it's not only the HackerNews regulars who can read HackerNews comments.
If you're really worried, create a pseudonym and post under that. Probably a better option is to take the bull by the horns, post as yourself and use that as an incentive not to post stupid things.
I realise that things I write can be linked back to me, but I want to not make that too easy.
I haven't posted anything stupid.