upon re-reading the old clancy letters i realized how connected these phrases feel to them. (these are quick thoughts not fully fleshed out so i HIGHLY reccomend reading the trench era letters again with the shirt phrases in mind!!) :
seldom surface - clancy's whole view on everything changed completely when he discovered trench, destroying the solid foundation he used to see everything through, he's exploring a complete unknown area with no sort of grounds to begin to understand what it all is (this one is a little more abstract than the others but still works)
no kin - clancy wrote about feeling alone when he was first exploring trench, he saw himself as a single soul in a vast unknown world
do you feel at home - clancy wrote alot about his struggle with feeling at home, inbetween dema which was all he knew as a person before escaping, though he was at some point convinced it wasnt his true home, and trench feeling more like home at times, his struggle with deciding which is his true home is consistently shown through out the letters
is this really you - this ties in alot with clancys questioning of where his home is because your home ties in with your identity, he's consistently trying to figure out who he really in this world
i just cant seem to figure out why. once again i highly reccomend reading the trench letters again with these in mind im like 99% convinced that this is what theyre referring to.