No, it really isn't. Consent is both a very straightforward thing and a very complex thing. Straightforward in that no means no, complex because issues around informed consent, capacity and equality in relationships aren't always as clear as we would like.
Between children you can have a situation where they are playing "doctor and nurse" type games, showing, touching etc. They may not have an understanding of sex but agreed to the game they were playing, they grow up and realise it's not appropriate to touch your brother/sister and feel shame for something that at the time felt ok but now feels very wrong.
That's a very different scenario than a child forcing unwanted contact in another or indeed a husband raping his wife, but can result in feelings of shame and pain which then lead the person to question the nature of what happened.
And, for the record, I am a survivor of childhood sexual abuse perpetrated by a child and no, I don't for a second question my experience.
