Most people are very possessive about their names.They have grown up with their names and don’t want others to take any intended or unintended liberty with these.If you abuse someone, he may ignore it, but if you call someone by a different name, he will most certainly mind. This is blasphemy you can’t be allowed to commit.
Try calling Shyam as Subodh and Rani as Renu.You will hardly have any scope of prolonging the conversation. If any conversation does take place at all, it may not be to your liking.
Most people expect others to remember their names after the first meeting itself. They have been used to people calling them by their names effortlessly. It comes to them as a shock if someone cannot recall their names.
People also take offence if someone misspells their names. Before sending out invites for weddings, get-togethers, etc., spend some time getting the spellings of the names of the invitees correct. Of course, you may safely avoid this procedure for those you don’t want to attend.
If you want to impress someone, spend some time memorizing his or her name. Practise pronouncing it correctly. Nothing more is required to satisfy his ego. If you can call someone by his correct name, it may not matter even if you call him names.