Not in childhood, no.

I think you are obsessive about these thoughts. But no - I don't think those thoughts are terribly unusual in themselves. I think many many many people have sexual thoughts like yours.

So many many many people have sexual thoughts about many many many different things. We are sexual beings. Children are sexual beings. Part of my work is with young people and am no longer shocked by any sexual things that children do. Normal healthy well-adapted children stimulate themselves, each other, masturbate, grind themselves against tables, furniture, animals (yes! they do that!). Children are curious about adult bodies, each others bodies, their own bodies, and animals bodies too. Many children have explored sexuality with same aged peers and younger peers. It is a NORMAL part of human sexuality. The adults job is to teach children where and when those behaviors are acceptable. (ie in private)

It becomes problematic when children are taught to be ashamed of their bodies.
It becomes problematic when a much older child forces a younger child against their will.
It becomes a problem when you reach maturity and act out sexually inappropriate ways, such as breaking the laws of your country. If you are an adult filled with all kinds of impulses about sexual behavior that violates the laws of your country and you are unable to control your behavior, then you need help to develop control over those impulses. If you are an adult and haven't broken the laws of your country then you're all good.

But seriously. FORGIVE yourself for what you did when you were a child. You were a CHILD and society doesn't hold children legally accountable for actions for the simple reason that they are children. If you are an adult now your job is to not act on those impulses but to choose morally and legally acceptable behavior instead.

If you have had sexual thoughts about children but have not acted on them and have the self control to continue not act on them, then you're all good. Welcome to humanity and the world of sexual impulses.