This is from the enormous anthology of distich poetry assembled by Barthold Nihus, Epigrammata Disticha, published in 1642; the poem is by Bernardus Bauhusius.
Ne puerum mirare, senem ne sperne; tametsi
Saepe vir in puero est, in sene saepe puer.
The vocabulary is keyed to the DCC Latin Vocabulary list. There are only two words in this poem that are not on the DCC list:
spernō -ere, sprēvī, sprētum - scorn, reject, despise
tametsi - although, though
in: in, on (+ abl.); into, onto (+ acc)
mīror mīrārī mīrātus sum: wonder at, marvel at (+ acc.)
nē: lest, that not
puer puerī m.: boy; slave
senex -is m.: old man, elder; senior, older
sum, esse, fuī: be, exist
vir virī m.: man