Discussing Cause - 1(Revised)

I think it is very important for me to choose my major in senior high school or college. First of all, it is not a subject only and possibly has something to do with my jobs in the future. Next, I must be interested in that major, or it will be a hard time for me to learn its details. It's because if I don't like or have no interests in the major, I will not want to learn it more; needless to say, specialize in that major. Finally, once I choose the major, it will be very problematic for me to give up and choose another one afterwards. It means that I have to restart and learn new things, and I will lag behind those who learn the major earlier than me. So, thinking twice before choosing a major is essential for it may accompany me throughout my life.