One time this fellow approached me in the grocery store parking lot. Claimed to be diabetic and didn't have money to purchase his insulin. He was clean and well mannered. I told him that we could go back into the store and I would purchase his medicine for him. 

All of a sudden, his medicine wasn't at THAT pharmacy, it was at another one, not affiliated with that grocery store. I asked for the location of that other one - he didn't "remember". He just wanted five dollars to fill it. 

I ended the conversation and he left to try his schtick on someone more gullible.