i am sad that i did n't drive my mother to the airport why ? was it because you did n't take those last few moments to spend time with her ? sometimes we have so much going on , we do n't have time to do it all ! i had an emergency at work . i am a doctor and it was a life and death situation : ( but now i regret because i could have assigned someone else and driven my mother because that was her life visit oh , no , i 'm sorry to hear that . you had no idea that would be the last visit , but i can understand how you would feel that way . i have no doubt she understood why you did n't though .
The cause of the sad feeling is missing an important life event for the mother.