This rhyming distich comes from the Florilegium Gottingense edited by Voigt.
Cum Fueris Felix
Cum fueris felix, multo stiparis amico;
Prospera mutentur: respice, solus eris.
The vocabulary is keyed to the DCC Latin Vocabulary list. There are two words in this poem that are not on the DCC list:
prosperus, -a, -um: successful, lucky, prosperous
stīpō, stīpāre, stīpāvī: crowd, press, surround
amīcus -a -um: friendly; (as subst.) friend
cum: with (prep. + abl.); when, since, although (conjunction + subj.)
fēlīx -īcis: lucky; adv. fēlīciter
multus -a -um: much, many; multō, by far
mūtō -āre: change
respicio -ere -spēxi -spectum: look back, regard, consider
sōlus -a -um: only, alone; sōlum (adv.), only, merely
sum, esse, fuī: be, exist