Choice: Truth or Illusion

After an exhaustive day of work and lectures yesterday I was trying to sleep early yesterday but just could not change my body clock at my will। So I just kept lying on my bed (determined to sleep early so that I can get up early) thinking about my decisions in past। The first which came to my mind was of branch change from electrical engineering to mechanical engineering in after my first year in engineering.
At that time I knew that placement scenario, cut-off marks, profile of students etc... is much better in the mechanical branch than electrical. But at that time I said that "It is my interest in mechanical branch for which I have taken this decision". This is the first decision. Eventually after 4 rigorous years I became a "mechanical" engineer and applied to US universities for my master's. After getting admitted in University of Cincinnati for MS in "mechanical" engineering I started my efforts to again change my department from "mechanical" to industrial engineering. At this point I justified my decision by saying “After working one year in software field it's hard to study core technical mechanical engineering again". But today I think I was lying to myself. It was the good placement scenario in COEP which compelled me to take a branch change in COEP and it’s the same case here with Industrial engineering. So that means I never had interest in any field!!! I just convinced myself by making excuses like "career interest" and ”software experience". So ultimately I started to conclude that my decisions were based on socio-economic conditions and not on my "interest" ... I kept on validating my decisions the whole night. Sometimes I felt that I was correct and sometimes I felt I was wrong..... The battle went on without a result till I felt asleep sometime late in midnight.