Being Committed vs Spending All One's Timefleeting
being committed vs spending all one’s time
Telling someone that something will be done does not necessarily mean that one will spend all one’s time on the commitment. It only says that the thing will be done by the end of the committed period.
In the morning, you are allowed to take your coffee without moving all your commitments forwards, and you should feel confident not doing what you are not doing.
In the case of scrum, I think that the sprint goal convey the same meaning. If at some point one scrum team member cannot work toward the sprint goal, it only means that per does not have the appropriate context to move it forward, so per should feel confident not moving it forward and focus on something else.