Teaching Responsibility: When Does it Happen?

I have been hearing questions such as… 

“How can I get my two-year-old to pick up his toys by himself?” (You can’t.)

“Why does my teenager say she’ll empty the garbage and then avoid doing it unless I nag?” (She has a gazillion other life questions plaguing her.)

“Why won’t my kids be responsible and just do what they know they should do?” (Do you always do what you know you should do—especially when someone else demands it of you?)