[handmodel]

I think about this a lot too but I think it just has to do with the way memories are stored in the brain - not anything to do with time itself.

It's sorta handwavey but I've seen it explained that at age 40 a year represented 2.5% of your life while at age 10 2.5% of your life (especially your post baby life) may only be a few months.

And to put it in terms of some advice I do think time moves differently depending on how much new memories you are taking in. Vacations to me can seem to be very long while weeks where I settled into my normal routine flew by.