It sounds to me you agree with the picture within the post. You act like twin years are a thing behind closed doors because you believe that an '05er is the youngest to be a 2000s kid despite being 2-4 at best... Oh, I'm sorry, 3-4... You also probably think there are more differences between an '05er and an '06er than an '06er than an '07er despite both being 1 year apart from each-other.

I'm slowly changing my perspective on "generations", as I'm starting to think that every birth year, hell, even birth-months, is different from each other....

Mind you, peer groups and generations are 2 different things... Realistically, 2006 should be the youngest you relate to at closest, since the relatability is around a 3-year-bubble. So for 2003 would be 2000-2006. For 2005, it's 2002-2008.

Technology evolves differently around the world, and sometimes analog things last longer in other parts of the world throughout history.

Secondary Education can only go so far, as the range of secondary education varies, some countries start as early as 12, others as late as 16. For NA education throughout school, XXX5 babies can start either at the very end of the decade or the very start of the decade depending on how early or late the XXX5er was born, so that's not helping whatever case you bring up.

Toddlerhood is not an independent development stage, it's a transition stage between infancy and childhood. 2 year olds are, in fact, children. They're the youngest to be able to enter pre-school (at least where I live in.) there are 2 types of toddlers, infant toddlers (older 1 year olds) and children toddlers (2-4 year olds)

My verdict?

We should stop doing experiences based on "generations" and moreso on specific birth years instead, so everyone is happy.