When riding crotch rockets, definitely because if you don't you can't see when going so fast. Also, back in '96 I was on my way home from an early am ride & luckily it was cooler on the Southern California coast that particular day because I had on long pants, leather jacket & gloves. I was 5 minutes from home when I came to an intersection with a van making a left turn travelling in the same direction as I was, blocked my view of any oncoming traffic. I tried to look around the van, slowed down and thought I've done this a thousand times carefully and flicked the throttle to accelerate.............then a little blue Mazda GLC made a left turn in front of me & the last thing I remembered was flying through the air, doing a front flip and landing on my back on the other side of the intersection. Luckily, the Honda Interceptor had the front of the seat meet the end of the tank like a skateboard ramp and I launched instead of being a passenger into the side of the little car. Needless to say I was sooo lucky to walk away but, I still have that Shoei 100 full face helmet with the little dots from the asphalt pavement making a faint racing stripe across the top of the brain bucket as a reminder of what can and will happen even if you're careful. Needless to say my guardian angel was with me that day because the guy at the dealer was shocked when he asked " who was the pilot on this bike?" and I answered "I was" and he said "and you're still walking?".
Anyways, full face for off-road and cold nights on the H-D, half helmets in states that require them & off when we're in beautiful scenic country and just enjoying the cruise where they're not required.
May your guardian angels always be with you!
Yellowsed