When you have invested something or someone you love — even if it's just an idea — you think that the investment you had made is futile and is lost. You cling on to it like a sinking ship, believing that this bad relationship would float back up from the cold murky waters. Someday.
Most likely, it won't get better, and the best way is to abandon ship and get yourself a fresh start before you get stuck in the ocean trench for the rest of your life. But it is easier said than done. The monetary, time, and emotional investments are too great for some of you to leave. Hence, you have fallen into the sunk cost fallacy: honoring investments that could never be taken back.