The day you realize your purpose will be one of the happiest days of your life. It is like waking up after years of sleep and realizing there is so much to be done. Your purpose, generally, is a way for you to utilize your passions to make a difference in the world, and this can easily become your life's work.
Starting Your Life's Work
Never forget, there is a difference between work and life's work. Most people are simply working; they have chosen jobs and even careers that have little to nothing to do with their passions, either because they have not identified their passions, or because they are afraid to chase them.
As children, most of us had a dream, an idea of what we wanted to be when we grew up, and most likely, that dream was squashed by adults who assured you it was unobtainable. Most likely you were told what sort of filed would be decent wages, and that was all that mattered, so you became that and never thought about your dream again. That dream could have easily been the beginning of your life's work, had you not been derailed.
But, that was then and this is now, and it's time to do what you love at this age and stage of your life. Finding your passion can lead you to uncover your purpose, and that purpose can't start out quite slowly, only to snowball into an entire life's purpose! Maybe you love animals and begin by volunteering at a local shelter once a month. Maybe that turns into more volunteering over time, which leads to the recognition of a problem you'd like to see solved. Maybe you think the animals would have a much happier time while waiting for their forever homes if they could play with each other more, even swim, and enjoy more consistent grooming.
This could lead you to helping improve the shelter where you volunteer, even taking a job there, and learning how you can write and apply for grants that can help you open your own luxury animal shelter, spa, and hotel. The sky is the limit once you find your passion and it leads you to your purpose.
And that is called your life's work!