There is a practice in today's internet culture of erasing the posts and tweets we're not proud of. Or maybe it was a blatantly wrong opinion that only after further investigation we recognize our error. The reaction is to delete the wrong and pretend it never existed.
We do it because no one likes admitting how wrong they were, and having proof exist for all to see. But also, we would seem wavering in our beliefs. To post an opinion only to change our minds later? We'd be frauds!
On the contrary, to have a historical record of your wrongs, discoveries, research, and then correction would be infinitely more valuable than simply a "correct opinion." If people see your struggle, wrestling with the facts only to change your mind, they too may be motivated to do the same. Instead of a society where people mindlessly follow those who have the right answer, we could exemplify a society of people who think for themselves.