John: It was wrong of you to blame me for that traffic accident  You know full well that the accident was due to my poor vision, and I certainly cannot be held responsible for the fact that my vision has deteriorated  Michiko: But I can hold you responsible for your hazardous driving, because you know how poor your vision is
People are responsible for the consequences of actions that they voluntarily undertake, if they know that those actions risk such consequences
Colleen was responsible for missing her flight home from Paris, because she decided to take one more trip to the Eiffel Tower even though she knew she might not have sufficient time to get to the airport if she did so.