On the point of driving whilst stoned. Confidence comes with experience. It may not be safe, but i used to smoke at a friends house and had to drive home. Originally we would make a point of giving it a few hours after the last joint tbefore i left so i could sober up a bit. As time went on that last smoke got later and later and i still had to leave by a certain time. Eventually this evolved into me smoking a joint whilst driving because it just made no difference (seemingly) to drive sober or stoned.

To your question i would say learning a musical instrument.

I spent years using a basic yamaha keynoard worth about 200 pounds at the time (when i was young) and until i found i was getting good and was joining a band i just used that. Eventually i bought a much more advanced synthesiser for around 700-800 and still have that 15 years later, im only just thinking about getting a replacement. (I had a few random pianos and synths in between and have a full size (basic) electric piano as well)

I worked in a rehearsal/recording studio for a few years and played in bands there and it was amazi g how many times you would see a new band of kids come in who could barely play baa baa black sheep but had spent easily 1500-2000 on their guitars and amps and insisted on bringing the amps and full drum kits to jams despite there being some fairly decent kits and and amps in the rooms already which were better for practice.

Some of them got good, but most of them would try to sell their gear to us before too long.

Im not saying you need to buy a cheap instrument and use it for a decade like me but dont spend 2 grand out of the gate and expect the skill to just fall into your lap.