Why Did BHO Change His Name From Soetoro Back To Obama?

One question about Barack Obama that receives very little attention is why did he change his name from Barry Soetoro back to Barack Obama Jr.? His adopted dad, Leo Soetoro, certainly would have had more of an influence on him growing up then his biological father, BHO Sr who abandoned him before the age of two. How common is it for an adopted person to desire to reclaim their original birth name especially when their birth father had little to do with them except being a sperm donor? Did Barry have a falling out with Soetoro and decide to cut him out of his life by repudiating his name? Was Barry/Barack an ungrateful son who spurned the man who was willing to take the responsibility of raising him? Although we're not clear if Obama actually bothered to legally change his name. can't it be interpreted as disrespect to Leo Soetoro? What was Obama's motivation? Does this give us more clues about Obama's true character? With the perfect storm conditions of 2008, he still could have been elected President under the name Barry Soetoro.