Does anyone feel that cannabis leaves your system way quicker than 30 days?

(I'm a little sleep deprived while making this post so hopefully this makes sense haha)

I feel the statistics online seem faulty for the average person. I'm not in good shape by any means and at the moment don't have a job so I'm not all that active and am on probation. swim gets a urine test done in a lab every month and a few of the months swim stupidly kept getting high off this weed they had stashed away. swim probably got high like 8 different days until about 14 days before the test and stopped. swim's done this a few times and have come out completely clean every time and most websites Ive seen unless I'm just ill informed have told me swim would most likely have failed. Now I'm not condoning what swim did as it was a completely stupid risk to take but has anyone else felt that this 30 days thing seems usually incorrect?