I don’t know about reincarnation, but I can tell you that my own personal memories extend back to my birth, and before.
I believe you. Same here.
I remember coming into my mother’s womb.
Same here, at least back to my birth. Up until I was about 12 I kept having a reoccurring dream. It wasn’t very exciting so I didn’t hold much significance to it. It always started in a room of a certain unique pastel green, and travelling down a hall of the same color to a doorway to a large room fours doors down and to the right from the first room. I remember huge globe lights along the hall ceiling as I was going down it. I drew out the shape of the globes and found a comparison color of the walls and showed her. She said “That was the hospital where you were born”. The hospital was closed by then and was going to be removed. I happened to know the son of the contractor who was going to do it. He got permission for us to go in and look around. There it was, the delivery room, hall, the color, the globes, and the nursery four doors down to the right across from the waiting room.