A two+ hour drive would really take it out of me. I would often have to stop and have a 10 minute nap.
I’ve found meds have really helped, I still feel tired, but I don’t have to sleep afterwards or take naps.
Same with riding motorbike, but double. I think it’s the intense concentration for long periods of time.
That’s the key. Actually, I have driven for a lot longer on unfamiliar roads which are interesting, so I don’t feel tired. It’s when it’s the same road I’ve seen a million times already that I get tired.
This sounds like you’re not getting tired because of driving or riding, but from being forced to sit through something boring.
I love riding my motorbike, and find that it wakes me up, and brings me out of a bad mood. I do get tired after a long ride, but it’s a good tired, not feeling drained.
If I’m forced to ride on the same old busy roads into the nearest city and back though, I feel irritable and drained afterwards. It doesn’t help that I’m in Wales, and we’ve had artificially slow speed limits forced on us, with penalties for exceeding them, so it feels more like an exercise in concentrating on the speedo, rather than enjoying the ride.