there could be other things at play like the fact that you have more time on your hands when you are a teenager compared to later in life when you have to work.

there could be other things at play like the fact that you have more time on your hands when you are a teenager compared to later in life when you have to work. and if you are working more and skimping on sleep then not all of the things you read will get into your long term memory. less distractions as well depending on when you were a teenager