@jan Here are some ways that someone could have "sort of" seen a laser light show, or not:
* Don't remember the event because too young
* Don't remember the event because too drunk/stoned
* Fell asleep
* Went for another event, but laser light show was demoed for some reason
* Laser light show at another venue
* Similar light and sound event at a planetarium, but not with lasers
* Have laser light show equipment for personal use
You might be able to come up with more!