This means, paraphrased, "I came, I conquered, I slept."
It is a wordplay on Julius Caesar's "veni vidi vici" (I came, I saw, I conquered).
There is a widely circulated version "veni vidi dormivi" (used on t-shirts) which means "I came, I saw, I slept." Another version is "veni vidi volo in domum redire" (I came, I saw, I want to go home).