Fixing Punctures / Puncture Repair / Exploding Tubes

small multi tool, co2 canister, pump, tube, park patches, all fit in my jersey pockets.
seems odd that people go on rides with a bag when at most a small saddle bag is all you need.

Yup. Puncture repair stuff fits in the back pocket of a jersey or jacket, no problem. I definitely enjoy the bike more when there's no bag on my back. Maybe you could get a plain-looking gilet or jersey for the summer.