Why the 50+ forum? This should be in General.
As the public relations campaign sign says "20 is plenty."
But they don't specify 20 of what; speed limit, or something else?

No need to be stupid, but enough to be fun ought not be a problem.

Here in Washington, the revised code 46.61.790 exempts cyclists from operating a vehicle while intoxicated. The most a cop is allowed to do is offer assistance & impound your bike for your own safety to later be returned at no charge. It seems the government would rather the DUI people ride bikes instead of drive cars.

So I say have at it. A bicycle presents very little risk to the rights of others & it's unlikely you are going to be very fiercely competetive while high on weed.

In all honesty, self-medication around 8-9pm every night is the only way I can get to sleep. Insomnia is misery.