Purpose, or as the French call it “raison d’etre” and the Japanese call it “ikigai” which all mean “a reason for being”. Viktor Frankl, a Jewish psychologist who was a prisoner during Nazi Germany wrote Man’s Search For Meaning and he implies that circumstances do not make life unbearable, it is only when we lose hope does life become unbearable. It doesn’t matter what your purpose is, it only matters if you believe it.
To be convinced that your purpose is for you; it must be something you love to do, otherwise you may feel empty, it must be something you are good at, otherwise you may feel uncertain, it must be something you can earn a living from, otherwise it may be unsustainable and it must be something that serves the world or you may feel useless.
Purpose gives direction, and if you didn’t know your purpose then your purpose would be to find a purpose; starting with what you love to do or what you are good at and see if that can be of service and earn a living.
You are not limited to one purpose and may have several. Some dreams may be big and some dreams may be comparatively insignificant. Dreams give direction, direction gives purpose and purpose leads to a healthy self-esteem.