How tough is it to be a physicist?

I'm considering it as a career, but I don't know how intelligent you have to be to write papers on a consistent basis and be a decent physicist.
In all my math/science courses I'm getting mid-high 90's without trying, but is this enough?

there is no way to judge based on your K-12 performance whether or not your will be capable of independent research.

you may be confused in thinking that talant plays a big role, its really a lot about putting the time/effort into your work, whatever talant you may have only helps with speeding up the minutiae.

somewhere along your academic career, your talent will start paying less and less dividends. at that point, many people that have been skating by on talent will suddenly decide they really aren't 'smart' or 'good at subject X' and that they should stop and go find something they're good at(where they dont have to try hard), the rest will perserviere and start working hard to understand the increasingly difficult material and possibly succeed in their field.