I was looking for a translation of the German expression "bevor ich mich vergesse" (lit. before I forget myself) and looked up if the literal translation could be used. In German this expression conveys a threat or warning.
However, looking at several dictionaries confused me a lot as the dictionaries seems not to agree with each other.
The first two quotes I provide below get close to the German meaning, but unfortunately they don't provide any examples. All the other ones have a totally different meaning.
forget oneself: to forget one's manners or training. (Said in formal situations in reference to belching, bad table manners, and, in the case of very young children, pants-wetting.)
John, we are going out to dinner tonight. Please don't forget yourself.
forget yourself: to act boldly or arrogantly. Phrase used to humble a person.
I believe you forget yourself sir!
forget yourself: to behave in a way that is not socially acceptable
I'm forgetting myself. I haven't offered you a drink yet!
I'm pretty sure that each of those definitions is correct, but probably some of them are only true for certain dialects or set of dialects.
I think my question now is if you would hear or say "forget yourself", what does that expression convey? Which of the definitions above could be applied?
Is there a definition which is acceptable for most dialects, i.e. is any of those understood in most parts of the world?
Finally, can this expression used as a threat or warning as in German?
Hau ab, bevor ich mich vergesse. (lit. Take a hike, before I forget myself.)
Verschwinde, oder ich vergesse mich gleich. (lit. Get lost, or I'll forget myself.)