I am afraid, dear Ebes, that Tradition is much longer and deeper than your and my memory of what we were taught in catechism. The very essence of Tradition, indeed the only reason that we stand on Tradition as well as Scripture, is that Tradition grows, develops, evolves. In is more that scripture, and that is the whole point. 

I assure you that the faith of the apostles was significantly different than the catechism we both were taught. To take the most obvious example, the concepts required for us to confidently profess that Jesus has both human and divine nature, and that God is triune, did not exist in their heads. We read these crucial truths from Tradition back into the scriptures, but that does not entitle us to assume that what we see, was what the first readers saw.

What makes this all sensible is our believe that the organic evolution of Tradition is guided by the Holy Spirit, and she invites our further evolution under her loving guidance.