The mystery of the Most Holy Trinity is the central mystery of Christian faith and life. It is the mystery of God in himself. It is therefore the source of all the other mysteries of faith, the light that enlightens them. It is the most fundamental and essential teaching in the "hierarchy of the truths of faith". The whole history of salvation is identical with the history of the way and the means by which the one true God, Father, Son and Holy Spirit, reveals himself to men "and reconciles and unites with himself those who turn away from sin".
This diagram makes the mystery clear as mud.....Just kidding,
It does represent that each identity is a unique being, yet all are one at the same time.
Even though Saint Patrick considered himself an uneducated and simple man, he used the native shamrock to explain the mysterious Trinity to the people of Ireland. He asked them to picture the shamrock (The whole plant - stem and leaves) as being God, and to picture each leaf as each person of the trinity (The Father, The Son, and the Holy Spirit)
Three separate leaves yet one plant.
I think I am beginning to understand.......