St. Patrick used the shamrock to explain the Trinity to the Irish people.
The shamrock also reminds me of the trinity and importance of Vision, Purpose & Mission. The following definition of Vision, Purpose and Mission is by the late great Thomas Leonard founder of Coach University and Coachville.
What YOU SEE as possible for others, the world.
Why you are here. What you are here TO BE.
What you are here TO DO. Your specific actions, tasks or goals to realize your vision and purpose.