Mudita is defined differently and in its essence, Mudita defined by other articles is "taking joy in the joy of others" or "feeling joy in the good fortune of others". Simply put, by way of observing the natural world with a righteously open and radiant heart, seeing the others experience of joy will in turn fill us up with joy.
Here is an easy example, especially for my parents out there (animal parents, this applies to you too)...
Have you ever been in a moment with your kids or animals where you are simply soaking in what they are doing? That sort of experience where you are fully immersed into watching them do whatever they are doing? And in that moment what you are watching is them experiencing joy, be it rolling around all cute making silly noises like dogs do or your child singing songs at the top of their lungs with the most proud standing body position with all the theatrical arm movements and twirls...THAT is mudita. THAT feeling you get from being so immersed into the moment truly absorbing what the other is feeling. I am sure we have all experienced something like this. Perhaps it wasn't our child or pet animal...maybe it was a movie, something fictional perhaps?
You see, Mudita more than anything is an experience of being so fully present in what you are observing that you remove your own obstacles that prevent you from feeling the richness and fullness of life. Yes, we can fully observe horrible things and is that still considered Mudita? I'd like to think not but this is only me interpretation of it.
For integration sakes, how can we begin a practice of Muita? It all starts with observing. Spend time to just literally look at things, people, without judgment. Be as indifferent about the moment as possible, no thoughts on it one way or the other. Remove your ego and simply be with what is and if what you are watching is something generally positive or neutral, discovering joy in it becomes inevitable.
My personal Mudita practice - watch wildlife, even the smallest of creatures
I LOVE rollie pollies, love them. They bring me so much joy. My Mudita practice becomes full fledged when I see a rollie pollie, I have created the association with joy and rollie pollies. It all started one day just purely observing them. If you watch a rollie pollie, there is nothing overtly fascinting about them and this is where Mudita gets interesting for me...remember how I said earlier that Mudita is a practice for positive or neutral experiences, well, watching rollie pollies would be considered neutral. Even in such, just by way of being fully immersed into their beingness, brings me deeper into my own where the greatest joy imaginable resides.
Let me know in the comments how you plan on approaching your Mudita practice :)