A great quote sticks in my mind, shared with me by a founder who was going through hard times with his startup. The company was going through a bad spot, and one of his investors suggested just giving up and returning the existing capital to the investors. An advisor then said: "It's not their money anymore. Don't you dare give up." He didn't, he persevered, and the company had a fine outcome years later. I would not…
I burnt years of my life following advice like this when I was young and didn’t know better. If your formula is sufficiently wrong, which is the rule not the exception, you can’t make up for it with perseverance. There’s a selection bias in these stories you hear. Stories about people who gave it their all and failed aren’t popular.
I guess the moral of the story is really be sure that you are holding a losing hand, and that you can't play go fish instead of poker.