Not all of the world is as obsessed with "tracking" -- or tracking by name(s) -- as some of our "leaders" are. This "several names"/multiple names phenomena is rather common in various cultures in the world ... from Western Africa to parts of Europe (including certain Roma groupings) to Central, SW, South and Eastern Asia and islands in the SWP. People using two names or variations thereof (or even more) happens far more commonly than people -- living in cultures where European/Europeanized/European-derived cultural norms are most prevalent or highly influential -- realize. In some places, people's names change* (or new names are adopted) when they have children; in others, people's names change depending on their age or the age/position of the person with whom they are dealing; in others, people's names change based on whom they are dealing with; in others, their formal name is not to be spoken but may be written but government documents may be done in one or the other; in others, the formal names change based on age and status; and other such variations.

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* by "change", I mean a different name from another name is used