There neither is, nor can there be, such a thing as an adult baby. The reasons are obvious. So what you are doing is cherry-picking or outright trying to re-define "baby" to suit your wants. This means you are using adult characteristics to "edit" "baby". That is basically dishonest by either knowingly, or willfully unknowing, trying to force your falsehood onto the real world. To try to do this full-time means you are living a lie and you either know it or have willfully damaged your mind, which is the faculty by which you maintain contact with the real world; i.e. awareness and sonsiousness, and is your primary tool of survival and of happiness. The closest you could hope to come to being a full-time any baby at your age is a lobotomy, which they do not do anymore, except maybe in China or Russia. Your next best hope is in being constantly heavily stoned or drunk with all your teeth extracted and a big chunk of your colon and your bladder damaged or removed. Then you have a shot at it. Even then, albeit not willfully, a baby tries to improve its life and gain more autonomy unaware that it is doing so