I see tattoos over scars all the time. They sort of work and sort of don’t. The scar takes the tattoo ink less well than the skin beside it, so its shape and some of its color can still be recognized. However, the tattoo does obscure it partly.
When you tattoo a person, you put the ink droplets between the transparent outer layer of skin (epidermis) and the opaque lower layer (dermis). The ink droplets don’t stay there long before they are eaten by macrophages. The macrophages then stay where they were when they ate the ink. Weird, I know, but that’s how it happens. If a mac dies, it bursts, and another mac comes along and redigests the ink.
The scar may have a very thickened dermis or the dermis may be replaced by collagen. The macrophages are not distributed the same way they are in intact skin. This is why the tattoo never looks the same over a scar as over intact skin. But it stands out less than it would without ink.
I say, if you want to go for it, go for it. Work it into a pattern, like put curling leaves and flowers along it as if it were a branch, then do a motto below it, and some sort of something symbolic of your life above it. It’ll at least give you something to talk about with the girls. And you won’t be shy about revealing your sixpack…
I wouldn’t go with the surgery motif. I heard the sound of hysterical laughter over the intercom one day. Went in and my most amuseable colleague was staring down at a dead guy with an amateur tattoo on his belly of a dotted line, with motto, “Cut Here.” When she finished laughing, she did.