I just looked in google... And it said that having sexual dreams abt one has nothing to do with your sexual desire in real life.. It means u may seek something with them... Like it depends with each scenario... But in your case u saw it with your younger self... Maybe it is bcz u wanted to tell young self of that time that u should have done this or that!?....
Like how we wish to have time machine to go back in time to save our younger self from embarrassing moments.....???
It can be anything...... Hope it helps...!!!

Is it pedophilia or incest to dream about fucking your younger self when you're 18??? I recently had a dream where i had sex with my 9 year old self and Idk how to feel