Can people do black magic just by knowing my age? I would partly say yes and partly, NO. This is why. For black magic to be effective and successful in its mission against another person, then it must establish some form of connection and or link with the intended target. This can be either be one’s name, age, picture and or place of residence.

This is therefore the reason as to why powerful spell casters like Chief Kyoga Henry, request for these details prior to the start of a spell casting process. The more information the spell caster gets about the intended target, the more accurate his spell or black magic gets good at achieving its objectives.
Therefore, in summary, one can do black magic on you just by knowing your age. However, you should also note that such black magic may not hit powerfully as that done when one has almost all the information they need about you.