Your mind finds it difficult to concentrate, unless it’s concentrating on your past. Then it’s like a dog on a bone, and every time you try to change a past thought, it growls at you.
The mind is certainly fickle. One moment it receives bad news and awfulizes , “Oh no, this is terrible.” Then, the next moment it receives good news and thinks, “Wow, this is great.” No wonder it’s so hard to manage your emotions and your thoughts from one moment to another.