(disclaimer, mostly lighthearted!) Cassandra as in Greek mythology who made true prophecies but they would never be believed.
DH and dc have an irritating habit of expecting me to know what to do/be in charge but repeatedly don't take what I say seriously. Not too serious a problem to be fair but I feel like calling myself Cassandra round the house to run the point home 
Example;
(Eating out) DH - "I really fancy the spag bol"
Me: "Oh, ok - that always gives you really bad indigestion remember?"
DH: "Does it? Oh, I think last time I just ate too much"
Me: "No, you say any time you have it you get a really bad belly"
DH: "Oh, well I'll just eat a bit"
Me: "Ok"
DH later - "I've got horrendous indigestion, I feel awful"
Me: (looking after him half the night because he gets quite ill with it) "Maybe you should steer clear of spag bol"
DH: "yeah, I'll have to remember not to eat it again"
bash head on wall
This happens almost daily over small things, I've tried just not pointing it out and hoping natural consequences kick in but DH just doesn't seem to pick up on cause and effect and dc seems to have followed suit. Or the consequences aren't on him/them! When the consequences are pointed out it's just "oh well, sorry, I didn't know" - maybe listen then!!
Anyone else get the same at home?