The idea
Under 18s are still children. The smoking age was raised from 16 to 18 but the right for men to have sex with boys was lowered to 16. Let's remove this and have one age where a person becomes an adult. The age of 18.
Why is it important?
It recognises that if a person isn't mature enough to vote or buy a pack of cigarettes, they aren't mature enough to have a sexual relationship.