@Tuna,
There is only an 'M' as far as that behavior we call 'reporting' is concerned. And that reporting can go on in our own heads as a process we might call 'conscious observation'. Heidegger's point, embellished by M, is that much of the time that conscious reporting is absent. Most of the time humans are on 'automatic' when neither 'self' nor 'object' is
evoked as separate entities.....and for less conscious species, that automatic mode(what Dreyfus calls 'seamless coping') may be the only mode of operation.
BTW. Languaging is a social activity involving the adherence of groups. The assumption that the above system implies 'solipsism' is ridiculous. Its place in epistemological terms is perhaps reflected by the chemical signals in an ant colony . IMO it the abstract persistence of
words as perceived 'objects' in their own right which leads to our assumption of persistence of
all objects they might evoke. The word 'tree' remains unchanged but that tree in my garden does not...neither biologically nor functionally according to my transient relationship with it. From this position, 'reality' and 'existence' are about contextually agreed
modes of reporting in order to co ordinate subsequent action.
You need to acknowledge that seamless coping as part of your own experience in order to commune with the above position. Just thinking about that inconsistent, daydreaming 'self' is one aspect of that.