In my early 20s I had a friend, well actually he was a bit more than a friend. He lived abroad and we had met a few times and had a bit of a holiday romance. We spoke online all the time and it was, I believed, a friendship.
But he then lost his job, and was going through financial issues (or so he said). He said he was sleeping in his car and asked me for money to buy food via Western Union. I suggested he ask his family for help, but he came up with lots of excuses. He promised he would pay me back and stupidly I believed him. So I sent him £100 (which goes quite far in his country). He wanted more than that. But I said that's all I could give, as I was a student myself with a small income.
Well, surprise surprise, I never got the money back. I know I was stupid to ever think I would, or to give it in the first place. I am not usually someone who is so easily fooled.
However, he did put pictures on social media within a week of him and his new girlfriend, who he had started to live with. Obviously he wasn't living in his car anymore 
I have no idea why he did such a thing to me, and I suppose I never will know. But watching things like The Tinder Swindler brings it all back, even though £100 is a small sum compared to what those women lost.
It taught me to trust no one
and that many people out there have no conscience.