Meaning of "have head in the wrong place"

What's the meaning of have head in the wrong place?

Is a 19 year old too young for a 28 year old?

I don't see it working out but there is no harm in trying. Most 19 year olds have their heads in the wrong place though.

Solution 1:

It means something along the lines of "they aren't thinking straight" or "they aren't thinking about the right things, or the things they should be thinking about". In the example you provided, it appears the statements are referring to a 19 year old having an intimate relationship with someone much older, which many would think is an inappropriate endeavour, or the result of not thinking things through clearly.

Solution 2:

Be certain, if you use the phrase, always to use a possessive to modify head. The title of this question makes a rather unfortunate omission.

The idiom being discussed here is

to have one's head in <place name>

as in

• He had his head somewhere else/in the clouds/in the wrong place,

and it means what the other answers say it does.

However...

This is a completely different idiom, with a completely different meaning

to have head (in <place name>)

as in

• He had head somewhere else/in the clouds/in the wrong place.

Executive Summary: Determiners are not always optional.

Solution 3:

Extremes might be "head in the sand" and "head in the clouds" (luftmensch). There's also "head in the game," that is, in the right place:

Eighteen thousand pounds of milk, as was suggested by Mr. Miller would not need over a twenty-gallon can of starter to ripen that cream properly. Of course I was speaking to the buttermaker that has not got his head in the game. If he had his head in the game he will not only have it on the starter, but will have it on the quality of the cream he is getting. His head will be in the game and he will see that he gets good cream. When you get cream that has gone beyond that stage, I do not think there is a creamery in Iowa large enough hold starter enough to make it good.

Seventh Annual Year Book Part VII, Iowa Book of Agriculture, 1907

Solution 4:

It means that they're not very sensible.