Do you consider male circumcision a necessary intervention in the life - young or old? I only ask because some Christian denominations believe so. I was circumcised as an adult. I only ask for your guidance. I accept that Jesus was circumcised. It was my Sunday School teacher who broached the subject. She told us that all boys should be circumcised like Jesus.
Since you are already circumcised, I don't understand your concern. What the Bible teaches is that under the New Testament law, circumcision serves no purpose. "For in Christ Jesus neither circumcision nor uncircumcision avails anything, but a new creation" (Galatians 6:15). Paul advises staying in whatever state that you are in. "Was any man called when he was already circumcised? He is not to become uncircumcised. Has anyone been called in uncircumcision? He is not to be circumcised. Circumcision is nothing, and uncircumcision is nothing, but what matters is the keeping of the commandments of God. Each man must remain in that condition in which he was called" (I Corinthians 7:18-20). In other words, don't go wishing you were the other way. Be content with whom you are.
What your Sunday school teacher taught was false.