Good Riddles

Question: Paul is 20 years old in 1980, but only 15 years old in 1985.How is this possible?

Question: A man goes out drinking every night, returning to his home early every morning. No matter how much he drinks, he never gets a hangover. This drink is very well known, but is rarely consumed, served warm and taken straight from its source. The man is a sucker for a free drink, especially since he can't live without it.

What is his favorite drink?

Question: You have a flashlight that takes 2 working batteries. You have 8 batteries but only 4 of them work.

What is the fewest number of pairs you need to test to guarantee you can get the flashlight on?

Question: I open to close but I close to open.
I'm surrounded by water but I'm never soaking.

What am I?

Question: I have more shoes than anybody,
but less feet than everyone.
I am met in the morning,
but departed in the night.
I may shake as if I'm angry,
but I won't bite.

What am I?