I have encountered a number of adult babies who feel unsure about their age when they enter little space. As a general rule, I would always recommend, so whatever makes you feel good and don't worry about age, and also this can fluctuate during the same session. You might feel like you want to not be verbal and maybe later you might want to say something and play like a toddler, and it's all fine. Check my blog piece about verbal and not verbal.
Some ABs have been more passive and look for a space of tranquility with me, and others have been very playful and creative, to the extend to really surprise me with their actions and way of reacting to activities, in a good way!
In the case you would like to perform something more 'realistic' in a way, or would like to at least know a bit more about it, this is a list of developmental milestones that you can have into consideration, always having in mind that there are no messy diapers in my sessions, so this will need an adaptation in the case of smaller stages (wee is okay).
I don't recommend you to perform a newborn, unless you want to be put in a cot and to sleep. Newborns would eat approximately every three hours, and that is the duration of my average session, so unless you are really tired and only want to sleep, newborn would not be for you. Equally up to 6 months there won't be much interactions other than very simple play, feed and hygiene as well as being put to sleep.
This is a very simplified list in case you are curious about it, of babies and infants development on average, understanding there where no learning difficulties or any other mobility or cognitive issue that did not allow this development. I don't recommend you follow this as a recipe, but you might enjoy recognizing certain behaviours as your preference (or not).
When you where 6 months of age you would have been able to:
Know familar people, recognize yourself in the mirror, laugh, take turns in communicating with others only with sounds, make squealing noises, close your mouth to indicate you don't want more food, you probably did not crawl, but where able to put up with straight arms with on your tummy, play simple games as peek-a-boo and smile at others.
When you where 9 months of age you would have been able to:
Be shy around strangers, understand many facial expressions (sad, angry, happy), know when you are being called by your name, many sounds repeating syllables such as "mamamama" or "babababa", lift your arms to be picked up, look for objects when they are put out of sight, bang two things together, sit without support, grab things with your fingers and move things from one hand to another hand.
When you where 1 year of age you would have been able to:
Wave good bye, call me "Mummy", understand when you are being told "no", look for things that someone hides, put things in a container, stand and begin to walk, copy me when we play (clapping or similar), drink from a cup and pick small bits of food with two fingers.
When you where 1 and a half years of age, you would have been able to:
Point to show something interesting, look at some pages in a book with others, help a carer to dress you by pushing arms through the sleeves or lifting your feet, be able to see a few words, and even put together three words, follow some directions with no gestures (such as "give this toy to me"), copy someone who is doing chores, play with toys in a simple way, scribble, drink from a cup with no lid, start to use a spoon, climb on and off a chair, play pretend, walk with no help...
When you where 2 years of age, you would have been able to:
Notice when others are upset, look at someone's face and figure out how to react according to it or in a new situation, point to things in a book, point to at least two body parts when asked to show them, use gestures like nodding or blowing a kiss, try to use switches, knobs and buttons, play with more than one toy at a time, show more interest in others, kick a ball, and follow simple instructions.
This now starts to be a bit more playful and fun, at least for me.
When you where 3 years of age, you would have been able to:
Show affection for your playmates, use sentences with 4 or 5 words, copy others, climb well, play symbolic games, participate in a conversation with simple and few words, ask "who", "what", "where" or "why" questions ("where is Mummy?"), say your name when asked and mostly talk well enough for others to understand.
There is no specific age for stopping using diapers, but on average this is in between 18 months to 3 years when children show signs of being ready to start to be potty trained, if there are no other conditions or developmental issues. Some would start training at 18 months and others not fully trained until they are 4.
I will in future create another blog piece with older ages.
Fluctuations in age are big. Would you ask your parents or carers if they are there for you?
Do you have any memories of it whatsoever?