"Too ticklish" is a relative phrase. Some may find they don't like being tickled past a point, or that they are extremely over-sensitive and dislike the feeling, hence they refer to it as "too ticklish". Some are "too ticklish" in certain parts of their body, so even though they may like it most other places, there may be one or two that they can't handle or might even be painful to be tickled there, so they may say they're "too ticklish" in those spots.
In short, I think it's possible, just depends on each persons individual sensations and like thereof.