Imagine uncontrollable weight gain - gaining upwards of 10% of your body weight per month. You have to buy a new wardrobe every two to four months. Your skin is stretching. Teeth are forcing themselves through gums without so much as a starter nail. Urination and defecation are done in your underwear and the only way to keep from sitting in it is to cry out for attention in hopes that someone will understand your limited ability to communicate. These conditions cause rashes over various parts of your body. The only thing you've had to eat for months is milk. Mobility is barely an issue, as you're straining to hold yourself up on your hands and knees, much less move in any desired direction. Sleeping is your only relief, and sometimes you are in so much pain, you have a hard time getting that right.
Welcome to being a baby.
Some of the good things include being waiting on hand and foot. You never have to move yourself, feed yourself, bathe yourself, clean yourself after soiling yourself. People sing to you, play with you, smile at you, and ask to hold you. You can touch a strange woman's boobs without getting slapped. You can cry without feeling oversensitive. All you have to do to brighten someone's day is smile at them.
Some of these things apply to adults, too. We've just forgotten. Maybe it leaves when you have to wipe your own butt.