A scuba-diving license is for life. In fact, it will last longer than you given that it’s coated in non-biodegradable plastic. Scuba certification never expires; no diving police will suspend it, cancel it, or penalize you for disuse.
One of the main reasons who so many people want to dive underwater is that below the surface, the sea life can be a breathtaking sight. All the marine animals and plants seem exotic and wonderfully strange, and they can give you a truly memorable experience.