
Originally Posted by
iCake
@Antonio1986
If this makes it easier for you to make sense of the phrase, then sure, think of it as a cut off from "что мне (надо) (с-)делать". I personally don't see anything missing in just "что мне делать". It's a fully sell-sufficient construction. Where мне just indicates the recipient of the action делать, that's what the dative is for after all, to indicate who's given something and that doesn't just mean an object, it can very well mean an action. This construction is impersonal, so it's very natural to use this to ask, say, your boss, what he wants you to do.
On a side note, I find it very curious that English speakers, for instance, prefer the use of "how do I do something" over "how to do something". E.g. A google query: "how do I install Windows" - 160 million, "how to install Windows" - just 34. From my Russian point of you:
How do YOU do something is your business, you're asking how others did that or rather for (a) successful way(s) of doing that, which others have already worked out. So an impersonal structure that should be.