Age and Maturity in Reincarnation

This thought popped up a few days ago, but we conventionally relate age and maturity in direct proportion to time and experience. We experience a linear progression to age with time (even though, age, technically, should be a more physically related idea) and much of our thoughts about it is the same way. Maturity is a more complicated metric in that it shows through an assessed growth from overall and cumulative experience -- both quantitative and qualitative. Other factors like culture, relationships, environment, age, physical, social and mental development are also part of that. Age and Maturity are closely related in that sense.

Reinncarnation basically subverts the linear association to the experience of age and maturity. In a lot *and i mean a fk ton cough* of works, the MC will count their lives lived in their 2nd life as their "actual" age. Say you died 20 years old before you reincarnated, so the following 20 years you lived after that is considered additive to your actual, mental maturity, age or experience (40 years old). It's normal to agree to that sentiment, but I've been thinking that that might not actually be a fair assessment. Living an environment with cultural and relational interactions unique to age 0-20 and repeating that is vastly different from living one life until you're 40. You have never experienced the cumulative linear progression of one who has lived 40 years--at least, you have never reached the maturity of someone's who's 40. Perhaps you can apply that to our experience with age (since we experience time as linear), but maturity would be very different.

What are your thoughts on this? Would you actually consider a reincarnated person's age and maturity as additive to their previous life?