I'm in the US and I'm fairly used to seeing metric for measures of liquid volume on items being sold. Most things are labeled with both measurements but some things (like wine and hard alcohol) are primarily (only?) in metric. I also used to make a lot of my own body products so I used milliliters a lot.
I'm somewhat conversant with metric distance measurements - my school district in elementary school was pushing metric hard, so I learned it young. I have a good feel for a millimeter, a centimeter, a decimeter, and a meter; but anything larger than that, I don't really have a feel for how large it is. I have a pretty good feel for how long a mile is, though.
Metric weights is probably the one I'm weakest one - I have no real good mental concept of how heavy a milligram, etc. is