Let it GO, let it GO!

I read a lot of blog posts, facebook statii, and tweets that advise us to "just let it go."
"Let go of the hurt."
"Let go of your past."
"Put down the baggage and walk away."
"Let go of his neck because you're going to get charged with murder." 

What I want to know is...
HOW DO YOU DO THAT?
Well, I mean except for that last thing, you just have to loosen your grip a little. Before the cops get there.

But seriously, how do you know if you've actually let it go?
It's still in your mind, right? You still remember it, yeah? It's not like you can take a Magic Eraser (although WOULDN'T THAT BE COOL??) and rub out the bits that you don't like.

So when people say they've "let it go", does that just mean they never speak of it again? Do they somehow box up the problem like "out of sight, out of mind"? That doesn't seem like letting go, it seems like burying it deeper in the dark so it can grow into giant fungus.

Because I don't understand how you can make the thoughts, and the feelings that accompany those thoughts, just disappear. I DO NOT GET IT.

I carry a lot of baggage -- I don't mean to. I don't DWELL on it. It's just there. The thoughts & feelings from the experience are there. I'm not holding grudges or still mad or upset about THIS or THAT or THE OTHER THING...I've forgiven people for hurting me - even if they don't know it.
So I think okay, I've let it go.
And then a situation arises that's similar and reminds me of THIS or THAT or THE OTHER THING -- so the memory returns and the feeling returns and although I wasn't *trying* to think of it, I wasn't *looking* for it...BOOM! Right back in the suitcase I'm carrying around.

So someone tell me...how do you really let something go? Or is that just another of those phrases that really means nothing when applied to Real Life?
#AskingForAFriend