When you’re head over heels about something or someone it means that you’re very excited, and/or turning cartwheels to demonstrate your excitement. It can also be used when you’re falling – he rolled head over heels down the hill.
This idiom is often used in the phrase head over heels in love with. It was probably first used in the 14th century, when it was heels over head, which makes a lot more sense. At some point the parts got switched round.
Similar idioms in English include upside-down, topsy-turvy, arse over tea-kettle and arse over tit.
In German you might be Hals über Kopf (neck over head) about something or someone.
There’s a similar phrase in Dutch, hals over kop (head over heels) but it means ‘at the spur of the moment’ or ‘in a terrific rush’. Although you could fall hals over kop in love, a more common expressions is hij moest hals over kop naar het ziekenhuis (he had to be rushed to the hospital suddenly).
In Italian you can say that your head is spinning more quickly than usual with excitement – su di giri.
In Welsh you can be over your head and ears in love – dros dy ben a dy glustiau mewn cariad.