I think one reason is that many of us do not reflect on the old year. What did we do? Why did we do it? Did our decisions and actions achieve the results we wanted? If not, what could we have done differently?
If you truly want to achieve your goals for 2015, I suggest you first think very strongly and clearly about 2014. Use that knowledge to develop goals and plans for 2015.
May you achieve everything you want in 2015!