People ask Google why their cat sits on them. Depending how and when he/she sits on you it probably means that he wants your attention because he wants you to do something. Or he simply wants to be close to you.
From my experience, if my cat sits on my chest when I am in bed, it means that he wants me to get up and be active with him. He also sits on me at this time to tell me he wants breakfast. Although he grazes on some dry food at night I give him high quality wet for breakfast.
I am convinced that he relates to me as he would another cat only he really can’t figure out why I don’t behave like a cat most of the time (I do sometimes to please him).
My cat becomes frustrated at my lack of activity at dawn (4am to 7am) as this is the time he is active (crepuscular activity). I try and explain to him that I am a human but he looks at me quizzically and gives up on my bizarre human behaviour.
In conclusion, therefore, if a cat plonks himself on you sitting upright, looking at you, it will usually mean that he wants your attention. We know that cats do other things to get our attention in the morning such as biting your nose or licking your face or prodding your face and so on. We should then figure out what he wants us to do. We’ll know that if we know our cat.
If your cat sits on you and then curls up – well, that can only mean he wants to cuddle up to you for emotional comfort and physical warmth.
Cats like to be physically close to their friends, both cats and their human companions. Domestic cats are quite sociable.
P.S. I almost forgot. When I allow him, my cat joins me in the bathroom when I am sitting on the loo. He likes the smell 😉 He sits on my shoulders and stays there until I have finished. I don’t have a photo of this!