Based on the information provided, John is a 28-year-old manager who does not have a family. It is impossible to determine if he is a computer games addict based on this information alone.

Currently, it is not possible to determine what John is doing at this moment.

In order to be good at playing computer games, a person should practice regularly, learn and understand the game mechanics, develop good hand-eye coordination, have quick reflexes, and possibly study strategies and techniques used by expert players. It is also important to take breaks, stay hydrated, get enough sleep, and maintain a balanced lifestyle to avoid developing addictive behaviors towards gaming.