This is an interesting subject. The biggest lie I have ever told has been to myself. I told myself that I was worth of love, and that was a lie. I told myself that she loved me( many she's in fact) and that was a lie. I told myself that I could look past many transgressions and continue relationships with family or with a lover, and that was a lie. Many times I felt that things would get better if I only loved enough, had enough patience, accepted what I was given. In truth, that is not good for anyone. A stone sober person cannot have a relationship with an alcoholic. A stone sober person cannot hold on to someone who choses heroin, meth, or coke over everything else in life.
The biggest and most damning lies we tell are to ourselves. I am proof of that.
I told myself that my mother loved her son. In truth, I was an anchor in her life. I was a status symbol. I was the result of someone going through the motions of what society dictates.
I was never meant to be more than a shoulder to cry on, a tool to be pulled out when there was a need. And it's taken a long long time for myself to come to terms with that. So many people have shown me my true worth to them. My mother painting the broadest strokes of all.
The moral of this is that lying to yourself is also the hardest to forgive. People make mistakes in life and can learn from them. Then you accept and move on. When you lie to yourself, the damage is worse because there is not place you can escape when your soul is raw.