I've mentioned this on a ghost thread, before. When I was 4, I had an imaginary friend. He was a teenage boy - older teenage. A bit random for a 4 year old girl, in retrospect! Thing was, I only 'saw' him in one place and he was like my friend, so I'd go there to visit him at dusk, most nights. I only saw him in the hen house! Used to sometimes go in there before we put the hens away for the night and my dad would let me stay in there for a bit as we used to love seeing the glow worms which were in there.
But I started going down there to see my Imaginary Friend. Told my parents about him. He spoke 'funny' and he had a foreign name I couldn't properly pronounce. But at the time, there was a French kid in my class at school and his name sounded, to my 4 year old brain, like this French kid's. (He was almost the only 'foreigner' I'd met). So I'd explain it to my parents that he sounded like So-and-so, the French kid.
His clothes were weird, too - although I can't remember how.
One day, aged 5 I remember, very clearly, announcing to my parents that Strange Name had visited me for the final time and I was upset because he told me I'd never see him again. I can actually remember this.
I never saw him again. Parents laughed it off as Imaginary Friend and 'normal'.
Nearly 30 years later, my dad sold the land with planning permission for a housing estate, and when it was being cleared by the developers and the foundations dug.... A few metres from where our hen hut had been, they found two stone sarcophagi. Roman, military.