Can lying to ourselves cause damage?

( Warning 18+ sentences in My Experience section) Do you lie to yourself? I think the question in the header is a genuine question to anyone actually reading this. I find myself sometimes in a deep state of thinking and self-reflecting. And have always been in the belief that, if someone self-deceives themselves. In other words, lie to themselves. That it would cause them harm in the long term.  What do I mean when I say that? Well to be very honest, I was raised around a lot of addicts. Family, friends, strangers, etc. One thing that I have grown to…