At least we know he never did.
On one occasion, at least, Jesus thought a centurion lived an exemplary life...possibly worth emulating.
Yes, Jesus marvel at his faith! The centurion KNEW that a servant is obedient to his master - the one he serves, whoever that is. What the centurion knew in the natural (his servants obey) he applied to the supernatural. The centurion knew whatever JESUS said, it WILL BE done for HE has the power over the supernatural and evil/sickness will be destroyed! He didn't have to 'see' it first to believe - that's faith!
"Now faith is the ASSURANCE of things hoped for, the conviction of things NOT seen."