So your parents taught you all the right things but failed to do the same for your sister?
When I got married at 26 I couldn't cook for sh*t. My wife was a little younger and all she ate was canned green beans and Cambell's Gumbo Soup. I had no idea how to manage a checking account, buy a house, or anything else.
We learned together how to be adults, the same way kids are doing it now and the same way they've always done it.
But they've got Youtube tutorials to show them everything they need to know. All the world's collected knowledge is right at their fingertips. I expect great things to happen once they finally take over.
Good coffee, good weed, and time on my hands...