Thoughts and other affections with propositional content are a special sort of contents of the mind to be distinguished from immediate, perceptual and proprioceptive streams which are a matter of pure qualia. This sort of distinction doesn't really work; the significance of all of that dimension of experience lacking significance is precisely that it appears not to signify anything but itself. It is deliberately non-signifying so that it can ground what is more properly signifying. And if you imagine some primitive form of life embodying a mind without significance then it would seem that the smallest touch of the latter anywhere in the system is enough to instantly contaminate all of it. Again, a bit like waking in the morning and instantly reframing every minute sensation into the waking world, from out of its prior, and otherwise meaning-filled, dreaming frame. The simple point is that there can't be a distinction between meaning and unmeaning as long as that is what the distinction is to mean. This is not to say that your whole world hasn't crystallised out of some primeval conferring, but that you can recapture that moment from where you currently stand.