Kryptonite was the fictional material that was able to drain Superman of his strength.
What is your kryptonite?
What people, environments and activities add to, or drain from your mental and physical energy levels?
How can you experience more of the positive and less of the negative?
You can start by learning to attune yourself to how your energy levels feel when you are engaged in activities or with people. Your body has the ability to read the environment and provide you with sensations and signals that enable you to distinguish between positive and negative energy.
Removing yourself from energy draining activities is an ideal situation but not always possible. So, if you find yourself having to be in toxic environments then you can learn to anchor your mind to thoughts that bring you pleasure. You can also learn to detox your mind after dealing with people that negatively affect your energy.
The key is to learn to listen and feel your energy. Identify your kryptonite. And move away from it as much as you can so you can preserve your superpowers.