Have you ever been in a certain situation and thought to yourself, "I've been here before?" or "I've been in this situation before?", but don't have a memory of when or where or can't place your finger on it?

Quite a bit. You get this very eerie sense of familiarity inside of a certain scenario, while having zero recollection of it happening prior. At times like this I wonder if spirit reincarnation has something to do with it. Perhaps in another life I experienced this.

I get that a lot and wonder if it is as often as the average person. It think a lot of times it is just the brain working faster than our recognition abilities.

Or, (I am about to sound hokey here...) we subconsciously predict and presume numerous situations, so we don't even know we will be in that situation for sure.

I say that because I get deja vu all the time when it has to do with my son.

I have deja vu, literally, almost EVERY day, and most of the time I can't even think of what it is that feels familiar. But like tonight, I'm watching Homicide: Life on the Streets (I have never seen the series before, this is still my first viewing of it) and I'm listening to a dialogue two detectives are having and I'm thinking 'my God, they did this in an earlier episode', but no they didn't, so I'm wondering where the hell that came from. But really, almost every day something sets it off.

Yup, from time to time. Then it would hit me later where that feeling came from. Sometimes it doesn't though.

Yes and I stop and try to think if I have ever been in this place before or done something like this, even if I feel I haven't.

I get those surreal moments quite a bit, actually. Where I'm in some kind of a 'scene' (sometimes just around the house) and it hits me that this is eerily familiar, and I can't understand why.