m1nr:
Isn't there something like your body physically and mentally goes through stages every 7 years?
I'm pretty sure I will not think the way I do 2 years from now and at 30 might even be a born again.. who the fuck knows.
I've never heard that 7 year thing before.
I'm familiar with Erik Erickson's 8 developmental stages (9 if you count the one his wife published after his death) that are psychological, emotional and physical tasks.
The basic idea is that you if you don't learn the task at each stage, you won't be able to get to the next one. Or at least get there successfully/without difficulty. Similar to Maslow's hierarchy of needs, you have to satisfy the "lower" needs before we are concerned with the "higher order".
The ages aren't arbitrary, but they're definitely not 7 year increments.
Infant (Trust vs Mistrust)
Toddler (Autonomy vs Shame and Doubt)
Preschooler (Initiative vs Guilt)
School-Age Child (Industry vs Inferiority)
Adolescent (Identity vs Role Confusion)
Young Adult (Intimacy vs Isolation)
Middle-Age Adult (Generativity vs Stagnation)
Older Adult (Integrity vs Despair)
This so-called Emerging Adulthood would fit between adolescence and young adulthood. I'd say adolescence is 13-19 and young adulthood is 20-40. I'm pretty sure Erikson defined Middle-Age Adult as 40-60. Anyway, 20-40 is such a large gap to clump a bunch of people together. As you said, you'll probably change twice before 30.
It almost seems like common sense, but so many theories and systems of therapy have been based around these stages.