Open Question: I have a black reddish n shape scar on left centre side of my forehead.(i dnt want any buffoon comments)?

I have a black reddish n shape scar on left centre side of my forehead.(i dnt want any buffoon comments)? i woke up one day when i was in 7th grade and there was this black scar or i dnt exactly know what it is. it is a mark or something but interesting thing is i never got it from burn or any fall, it just appeared. it's texture and color reduces so much some times tht it is not visible and smtimes it is very dark.In some of my photos it is easily visible and in some it is not there. hv been to doctors they dont know what it is, it never itches ya but it pains smtimes very occassionally.. last time it pained was 2 years back. even people continuously ask me tht how i get a wound there ..nd it was not some days back...i just reply it is there from last 8 years it just vanishes some times....I m very curious what it is???This is not a gimmick or something, i am 20 yr old boy i am thinking to go through laser to remove it but just want to know if someone in world knows what it is ??? and why it vanishes or lightens up and then on some days it is dark like a nip of pencil???(it is not even a birthsign as i never had it till 7th class not a bit of it)...so answer me if you can help.(i m looking forward to replies from people doing doctrates in dermotology or any one who has knowledge of this)