A cowbird doesn't weave nest of her own, and lays her eggs on others nest. If the owner (bird) of the nest suspects it, then she throws the eggs of cowbird outside nest or if it goes unsuspected, then she takes care of the eggs like her own.
Some people you come across in life, quite often, who would try to throw their worry/ anger on you, despite they are complete strangers to you. For example, that annoying sales person at super market or that frustrated driver at parking lot etc.
Choose not to raise the anger of others inside you. You have a lot of yourself to look after. Do not take over the garbage of anger or worry of others.
It is good to motivate someone and showing them the right path, but don't allow them to lay their eggs of worry & anger in your nest.