Yeah that shit blows my mind. Most of the people I know who talk to me about, "Oh yeah I'm going to get that next Friday when my paycheck comes in and I can afford it." or say, "Things are tight right now, I won't be able to pay for <some necessary item>" I just want to sit down with them and go over where they spend their money and see where the fat is.
My wife grew up in a family that spent everything they had, she came into our relationship with the 'afford' mentality. The kind of mentality that says, "If you want something and you can afford it, then get it.". She's very cheap and we don't have any financial arguments, but I had to break that mentality from her. I would tell her, "If you make your purchasing decisions based on what you can afford, you'll always be stuck making being limited by what you can afford."