http://www.fundeu.es/noticia/la-esquina-del-idioma-olvidar-4356/ http://www.hispanoteca.eu/Foro-preguntas/ARCHIVO-Foro/Olvidar%20y%20olvidarse%20de.htm (...)El verbo olvidar lleva complemento preposicional introducido por la preposición de solamente en su uso pronominal: olvidarse de. En este caso, la preposición de precede al complemento, sea éste un sustantivo, un infinitivo o una oración subordinada:(...)
Judging by your level I'm sure you know this by now, but just in case anyone else is wondering this. It looks like Olvidar and Olvidarse are regular and reflexive verbs that mean the same thing, and their usage only varies with location. Here's the link I found http://myspanishnotes.blogspot.co.uk/2008/07/me-olvide-olvidar-vs-olvidarse.html
it always depends if you are using the "tuteo" that is often used, a way to use the "olvidar" without the "se" is changing the order of the phrase, example, "que no SE TE vaya a olvidar..." if you have some tipe of relationship, or know that person if not, you can't use the "tuteo" that is the "te, nos... normally the verb that have in the end "s" like habla"s"..." when we talk formally like to your emplyer or when you are mad with someone then you use it like this "que no SE LE vaya a olvidar..." but you only have to change the order or more likely use the formal order of the componsition of the spanish sentence that is like this: Subject, Verb, and the predicate. it could go like this "Que ne se le vaya a olvidar..." like this or "que no se le olvide..." it always can be arranged like that.
I tried a response that was more literal and don't really understand why it's like using a double negative in English. I said, 'Of that I am not going to forget..' then it gets confusing. I tried saying 'not going to forget anything' knowing it wouldn't like that I didn't say never. I got it correct the first time so I can understand it generally but like I said, it doesn't work literally so I think I'm missing something. If my question makes sense, please help. Thank you