Ignorance of the law is no defence. Sure, some publicity might help to educate the public, but most small boys tire of pulling the legs off flies and playing with matches at an early age, as a result of boredom, sometimes painful realisation that their actions have consequences, or the acquisition of some semblance of intelligence and morality.
UK law has changed in two ways. First, the use of lasers is now a specific offence. Second, it's a strict liability offence.. In other words, you can't claim that you did it to test how well your laser pen worked or that you were communicating with UFOs, or that you had a very troubled childhood from which you've failed to grow up.