The thing is he flunked drug tests twice at Nebraska, too. Risking millions for a joint is flat out stupid. Doing it 3 times? Sounds like a low grade imbecile with a strong self destruct gene.
If he were a guy with a 10 Wonderlic score you might think there's a severe cognitive deficiency ("a low grade imbecile" as you indelicately put it) whereby he can't plan ahead for anything beyond the immediate future. Or perhaps he's a functional illiterate who's not able to read and understand the testing regime.
Gregory, however, is evidently far from being an idiot or illiterate, with Rapoport tweeting that he may record the highest Wonderlic at his position in this draft:
http://bleacherreport.com/articles/...rumors-and-speculation-on-des-nfl-draft-stock
There are a couple of things that point to the heart of the problem:
Gregory was quoted as saying, "I don't wake up every day saying, I'd really love to go smoke," he said. "It's not a struggle for me every day (now), it really isn't.
In the past, hell yeah, it's been a struggle. It really has been. Now, I'm focused on my dream."
http://www.nfl.com/news/story/0ap30...blame-myself-for-failed-nfl-combine-drug-test
After checking a number of sources, there is a rough consensus that THC clears the system in as few as 3 days in the case of a very occasional user, as detectible in a urine test. However, in the case of very heavy user, it could take 60-90 days. So if staying off the ***** has been a stuggle in the past, "hell yeah" even a smart guy with a problem is going to get caught, especially in college where a year-round testing regime is in place.
Bearing this out, we have the following:
"Gregory said he has not smoked marijuana since December, but because his THC levels were so elevated, the drug remained in his system at the combine. Thus, the positive test."
So, it comes down to (1) is that kind of "I can't help it" problem behind him and (2) does he need it to play the way he's played? That may present a greater risk than innate imbecility.