Says Wikipedia, the Romans admired palindromes ( reads the same backward or forward ), as demonstrated by In girum imus nocte et consumimur igni -- "We enter the circle at night and are consumed by fire".
Palindromes, a sort of symmetry in literature, seem to appeal to many of us at some level -- perhaps it's in our DNA.
Topologists like to note that the juxtaposition of the 3' end of one DNA strand beside the 5' end of the other at both termini of a double-helical segment makes the arrangement a "crab canon".*
*A crab canon is an arrangement of two things that are complementary and backward. Originally it is a musical term for a kind of canon in which one line is reversed in time and pitch from the other (e.g. FABACEAE <=> CGCEGFGB). The use of the term in non-musical contexts was popularized by Douglas Hofstadter.
Have you noticed the palindromes that we used on this website?
The palindromes were added to the titles as silly quirky larks -- squarks .