A Chip on My Shoulder

Good News, I get a new bed on Saturday! Bad News, I decided I would paint my room before the bed came in. Worse News, I decided I would undertake this feat while my intelligent and artistic girlfriend was out of town. How hard could it be? Take up a pillow case from my comforter set and choose a color I like. I was so confused, they all started to blend together and I really couldn't tell what would or wouldn't look good against the new sheet set. My comferter is boxed off with blue and green. Since my room has been pastel blue for the past 15 years of my life, I decided to go with a green, but alas, couldn't choose one of at least 50 different shades of green. So I went with a blue. After the nice lady at Home Depot who helped me choose the color finished mixing it, she took out a little drop and put it on the lid so I could see what it will look like. I take the can home, peel a chunk of paint off the wall, place the paint chip next to the sample, and shake my head in disgust. I walk in with green in my head, and walk out with THE SAME SHADE. What is wrong with me?!? I know full well what my walls look like, they haven't change in the past 15 years. What possessed me to waiver from my instincts, once more, what possessed me to choose the same color? I knew darn well that my walls were pastel blue, yet I still let the Home Depot woman show me paint samples from the pastel book. In a few hours, I will take my clone paint along with my chip and see if they can't tint the paint to something; anything different. I really would not like to have to buy another can of paint at $25, but if I have to, then so be it.