I haven't touched marijuana in years and if they legalized it tomorrow, I still wouldn't touch it. In my younger days, however, I smoked acres of the stuff.
That being said, the most dangerous thing about marijuana is having a drug conviction show up on a background check. More lives have been damaged by this than the drug itself.
From the linked article:
“ in 2007, the last year for which statistics are available, 782,000 Americans were arrested for marijuana-related crimes (90 percent of them for possession), with approximately 60,000 to 85,000 of them serving sentences in jail or prison.”
Ridiculous!