''1377'' is lett/lätt in leet speak which is swedish for "Easy". Used by swedish gamers/University students and leet speak enthusiasts in their daily speech. It is very much the swedish equivalent of that was easy.
Person 1: I got36 out of 36 points on my math exam!? But I barely tried.
Person 2: Yeah. I guess that's all it took.
Person 1: hmm... ''1377''!
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.