A man doesn't look at me and ignores me. Sometimes he yells at me, sometimes he laughs happily, sometimes he stutters, sometimes he is indifferent. What is the reason?

To sum up, this boy's mood is out of control, and his mood is particularly changeable, which will make him have no self-control. The reason may only be known to him. I think you should keep a proper distance from him, otherwise it may not be good to hurt you when he loses control. Moreover, such emotional people generally find it difficult to control their emotions and usually vent them on others. Don't provoke him too much at ordinary times