"What was I thinking when I bought that pig?"How many times have you asked yourself that question? Don't worry, you're not alone. It's an all-too-common lament among individual investors, whose portfolios are often littered with these losers. Almost as bad as the financial hit is the nagging related question, "How could I have ever been so stupid?" Today, we address that issue. Included in our discussion are two basic tools that will help you look back and understand your own thought process, and the analytical steps you took -- or failed to take -- before buying that sow. More importantly, this process can help before you buy the next pig.