This is another Yiddish-motivated question. I wonder if "träumen" was ever used in a reflexive construction, as in "es hat sich mir geträumt...". This is how the Yiddish phrase is constructed, except that we use the Semitic "khoylem" instead of the German "traum" for the verb.
Does our construction comes from an old German? Was "träumen" ever used as a reflexive verb?
P.S: We also have "es hat sich mir gedacht..." for "it seems to me...". I'm not sure if that flies in German too, does it?
EDIT: In response to the comment by Jan, we would have for the subjunctive case:
"Es wollt sich mir dos keinmol nischt ge*khoylem*t."
EDIT II: I finally got some feedback from some very knowledgeable Yiddishists, and they seem to find that our reflexive case is a back-formation from Polish. Specifically, for the case in hand, we have the Polish " snilo mi sie (przysnilo mi sie)" which becomes in Yiddish "es hot sich mir gekholemt".
Indeed, we are also allowed to say "ich hob gekholemt", but as my friend Lee Goldberg points out, there is a different nuance. The reflexive version is more passive, as in "a dream occured to me". Lee observes that Jacob's brothers might not have been so resentful if he had told them "es hot sich mir gekholemt" rather than "I had a dream...". Of course, Jacob did not have that option available to him as he spoke Hebrew rather than Yiddish.
(As an aside, I was previously using an incorrect vowel: there happen to be two vowels that sound the same in Hebrew, but one goes to "oy" in Yiddish and the other one doesn't. I've used the correct vowel in my last edit.)