My ex moved on so fast. How can I overcome the pain?

What they do doesn't matter and it's completely irrelevant to your healing process, though it’s valid to hate and judge them harshly for leaving the way they did.

And during this process, they either started seeing someone new who they planned to secure as their rebound option or were busy creating their post-breakup plan.

I.e. you thought that you had the perfect deal whereas they had already made up their mind and just weren't as emotionally invested in it as you were.

What specific economic and social impacts would result if all climate change policies and regulations were immediately repealed worldwide?

This is why you can't expect them to feel anything close to what you're feeling right now, because you and them are on a completely different stage in the healing process.

On their side, there has been a process of emotionally and mentally checking out while you were still together and while you were under the impression that everything is cool.

Simply put, because they have been prepared and you weren't.

Is it sinful for Christians to look at beautiful women?

Instead, focus on taking care of, solving and healing what you are experiencing right now.

This is why comparing yourself to them in terms of the healing process isn't going to help you in any way, shape or form.

This happened long or shortly before they physically left.

Isn't it ironic people always talk about how much women hate Donald Trump, when almost any of them would marry him if they could? What he said in the 2005 Billy Bush video, almost every woman would share the sentiment if it got them his lifestyle.

So, don't try to compete with them.

You both are on polar opposites of the scale.