Look closely at the location of the brake cables before I torn apart the Centurion in relation with the bars. Both cables are between the rider and the bars to the right of the stem. I always put my cables in front of the bars with my other bikes. Have I been doing it wrong all these years or did the previous owner screw up. Or does it even matter?

Behind the bar is the "traditional euro-pro" way to do it, AFAIK. For the rear, I can't see that it makes any difference. For the front, behind the bar gives a smoother, more direct path, so theoretically it might give you better braking. With modern cables and housing, any difference probably couldn't be measured. So the short answer would be "It's your bike - set it up the way you like."

SP
Bend, OR

I agree, but will still make fun of you if you choose to route your cables in front of the bar.

both cables running on the same side of the stem isn't really considered the norm.

You have been doing wrong all these years, but you're not alone.