Can you ACTUALLY convince someone to CHANGE their mind?

If someone is actually open minded, and not just looking to win an argument, than yes.

Sure.

We bothered you about your long posts and now you're down to one sentence.

With the right set of circumstances and people, yes. But don't ever try to change somebody's mind via social media or a message board. You might as well be talking like the adults did on the Peanuts cartoons trying to do that.

I think it depends on these factors:

1.) The person who has one belief.
2.) The second person who has a different belief and is trying to change the mind of the first one.
3.) Their relationship.
4.) The subject in question.
5.) The techniques Person 2 uses to convince Person 1 to change their mind.

It should also be noted that once someone has made their mind up, it's almost impossible to change their viewpoint on something.

I've had my own changed, in considerable scope - but I do recall being fairly stubborn about confronting all the bullshit, received unwisdom I had rattling around in my head beforehand. It embarrasses me now, but I'm grateful I was able to sort of grow up, and get to the truth about fairly important matters very much eventually. One huge turning point was spending time in Europe, seeing how different folks managed their affairs and realizing that it worked quite well.

The history is out there - but the individual has to confront the fact that they may be (drastically) misinformed, their political bias, or world view which informs it, may be so much a part of their identity that it constrains taking a fresh look at the facts.

So I would say the answer is yes, but its not a commonplace occurrance, probably requires an internal reevaluation. The willingness/capacity to test ones ideas/expectations against observed results, a responsible interpretation of the past, is the raw material for such changes.

No. The best you can do is plant seeds of wisdom/knowledge, and leave it at that.

Of course but the more deeply ingrained beliefs, the more difficult it is to convince a person to alter those beliefs.

Yes, but it is an option inception move than requires great patience and agreement.

I had my mind changed about a number of topics around 2009, having access to stuff on YouTube gave me a whole different perspective on the world.