Clear pattern in behaviour every month

Hi all,
Every month, I see a very fixed pattern in that he would be very attentive, kind, positive, lively etc. the day of the full moon and a day before and a day after full moon. However, after a day past full moon, he would not reply, be withdrawn as if the whole world has collapsed... I have not just noticed this in one month but every month!

Makes me wonder how the moon cycle can be so deeply connected to a person's behaviour and that surely, after all these years of going through this, he may have noticed the pattern himself?

Thing is I don't know which is really him.. the extremely positive attentive person at full moon or the completely withdrawn, silent, uninterested person from the days after the full moon? Shifts from 1 extreme to another.. every month it is the same...

He is: Gemini Sun BUT Cancer Moon, Cancer Venus, (maybe also Cancer Mercury),

Thanks

I wish you wouldn't think of it in terms of which is really him. They are both him.
Is it fair to ask if you are yourself when you are sleeping or awake? You're still you, just in a different state.

Why can't he be both? I mean every person is multifaceted and layered. THat is just part of who he is. I know I have my mood swings and go through my phases, as you probably do too.

I know that people do change in moods but this is such huge dramatic changes.. I feel that whatever mood I was in, if I really trusted/liked someone, I would still behave the same (but maybe slightly less interested when in the bad mood) rather than go from steamy hot to icy cold.. I know it isn't me who has said anything offensive, etc. although I did question it initially.

It is like he only works in extremes of either too much or too little.. no intermediate and it's just too much of a rollercoaster..

Thank you for all of your replies so far.

When I say "which is him", I kinda mean like sometimes people say someone is not their true self when drunk... could it be that he really has no interest/care in us but under the "full moon", is in a drunk-like state, where he simply just craves the attention?

There is not even 1 month, when he can be even slightly consistent throughout.

I think he has an extreme personality. My mother is like that, there are no in between states, just one extreme to another. I wouldn't stay that the full moon puts him in a state where he is "not himself", especially if it is a constant thing, that is just who he is