Dream of child, ignore

My dream began where I was sitting on my sofa when the bell rang. I opened the door to find Lisa Simpson, in a Girl Guide uniform, at my door, who asked me if I wanted to buy some cookies. Being a nice guy, I obliged and asked for three boxes. She said "So, OK, you want five boxes..." I was confused and said "No. I said I wanted three". Suddenly, she repeated, more forcefully this time, "You want FIVE boxes", before kicking me in the nuts and holding a knife to my throat, before repeating "You want five boxes. That'll be £102.50". I, scared out of my wits, nodded and gave her all the money in my wallet. She kicked me in the nuts again, said "Have a nice day" in a mocking tone and walked off, leaving me writhing in pain on my doorstep. I am male, British, and will be 18 in just under 2 weeks (my birthday is on Christmas Day). I am male, British, and will be 18 in just under 2 weeks (my birthday is on Christmas Day). I am somewhat immature in personality and often ignore people when they try to remind me of the responsibilities of adulthood. I am also not conventionally handsome or in shape and do not partake in any particular "male" activities (e.g. I am not interested in sports). I am also somewhat awkward with the opposite sex. I used to watch the Simpsons when I was a child; Lisa was my favourite character. I am wondering of the significance of this. I only started having these dreams round about now, when people reminded me of my milestone birthday.