Obviously people who are usually so strong, once they get tired, means they really are tired. They don't simply let themselves feel tired, they might have tried not to, but once they reach their limit, they will really become tired and have nothing to say anymore.
We do know what the consequences would be, but because we keep our ego and never want to hold back, and we thought the other side would stay strong as previously, thats why, we reach that state. The state when they get tired over things they never were. They are reaching their limit.
And its scary to know that this state is a state when their heart got nothing to feel afraid of. They are ready for anything.