You’ll know when you get there buddy.

https://en.m.wikipedia.org/wiki/Stoning

Pretty sure it’s when you get so stoned you can barely walk and everything is spinning and you’re sure that the weed is actively punching you but you’re not sure where. Then you sit/stand in front of a cash register and interact with people while time blurs around you and you are no longer sure if there are customers and maybe you’ve really just been pushing money off the counter for 3 hours and wow I think I made it to work on time.