I am usually aware of how I feel, but not necessarily 'why' I feel as I do, at a given moment or on a given day.
I am afraid of repercussions for expressing how I feel, or there is no 'place' for it, or it's incidental to reality, or it won't change anything, or it will only make my own life worse and accomplish nothing, or it feels like complaining and the words or myself don't have the 'value' to be 'entitled' to do so.
Or it will bring other's down/ be burdensome, etc. Because of all that and not being used to that or used to it without repercussions I'm not likely to find words or desire to do so, either.
Also, I 'fake it' well, and other's seem to be most comfortable with that.