Translation:I have fallen asleep.
Or a narration. Remember it's independent of time so can mean I had fallen asleep.
jIQongchoHpu'. pay' muvemmoH wewtaHbogh targh.
I have fallen asleep. Suddenly a glowing targ wakes me up.
I had fallen asleep. Suddenly, a glowing targ woke me up.
At least, that's how I tell stories, and you'll find similar in the paq'batlh epic translated by Marc Okrand.
Right, English has a general rule that when you tell a story, you tell it in the past tense. Klingon has no such rule — you don't have to position the storyteller in the future of the narrative. The storyteller is right there in the action with you, and it's happening right now.
But if you're telling about completed actions that happened in the past and you're not putting your perspective into the middle of the action, you'll need those perfective suffixes. This is more likely to be the case when you're reporting things to others. If, for instance, you see a Romulan Warbird decloak on your viewscreen and you know for a fact you destroyed that ship last month, you're going to say wa' wen Dujvetlh wIQaw'pu'! We destroyed that ship last month! not wa' wen Dujvetlh wIQaw'! We destroy that ship last month! You're not putting anyone in the moment of the destruction in such an utterance; you're reporting a completed action from a viewpoint after the fact.