Dave has probably invented time travel and he is taking some nanobot based anti-aging drug from the future.
That also explains why he has so many oscilloscopes. He is probably selling them as vintage equipment in 2050. They must be very pricey since unlike 90% of equipment in 2050 they don't require an online account in order to work.
They don't also need 50GB of updates every week to stay compatible with AI powered, cloud based, trigger as a service functionality.
Look! He even has blueprints for flux capacitor: