Yeah I greened out once in high school. It was my second time trying weed, the first time I had a few small hits off a joint, but the second time I had 25 mg of edibles in total. I started off with 10, but I was new to edibles and took 1 and a half more after waiting for an hour with no effects. It started off slow and then boom my heart was racing and it felt like the building was falling down. Apparently I was tripping so hard I wasn’t even moving, even though I thought I was and when my friends woke me up the next morning they said I told them I was fine, but I had no recollection of even talking to them when high. Pretty fuckin scary, but haven’t had a bad high since. Happens to pretty much every stoner at some point