Doesn't this assume that visible "thoughts" are the only/main type of "thoughts" and that they correlate with agent action most of the time? Do we know for sur

Doesn't this assume that visible "thoughts" are the only/main type of "thoughts" and that they correlate with agent action most of the time? Do we know for sure that agents can't display a type of thought while doing something different? Is there something that reliably guarantees that agents are not able to do this?