There were times that I did not wear a helmet, here in SC they are not required but have always worn one for the last 10 or 15 years. Started out with a full helmet, it was black so when to a half helmet, did that for a while but changed to a 3/4 and now use a Shark Evoline. I no longer ride without a helmet and my wife now uses a Shark Evoline. They are heavy but you have a choice on how you use it, full or 3/4.
Gear, I wear Sidi boots, the key is full ankle support, can walk in them all day if needed and they are Gortex lined to they can be worn in the rain with no problems. On my second pair and they need to have new soles.
Pants, I wear jeans made by Duluth. I, at one time, used "draggin" jeans, but they were not as comfortable as the Duluth ballroom jeans I now wear.
Shirt, depends on the weather, cold weather, a skin tight shirt that I can wear my heated jacket liner over with comfort with a leather jacket over that.
Warm weather, a cotton long or short sleeved shirt and a mesh jacket with additional padding.
Hot weather, depends on the humidity. I have no problem wearing the mesh jacket when the humidity is low, but high heat and high humid means a very hot body. I have tried he so called "cooling vests" and without low humidity I found it to be very unsatisfactory.
My rational for all he above. At my motorcycle safety class the instructor emphasized that riding a motorcycle was 90% mental and 10% physical. Which means you need to be comfortable to be safe and comfort is more important to safety than gear.
Anecdotes: I was on US 33 (I think that was the road) in WV one August. Stopped at a gas station, near place you could climb some rocks if you waned. Met two other bikers on "sport" bikes. They were what I would call ATGATT. Their faces were red, they were sweating profusely. Reminded me how important it is to be "comfortable" when riding.
Incidents: Two or three tip overs at low speed, one in a parking lot making a tight turn, broken ankle thats why the Sidi boots. Hit a deer on an interstate in WV at 75MPH on my ST on the way to Nova Scotia in 2014. Had to duck tape the side case to together, but made the trip no issues. Bike was repaired after I got home.
My riding experience is not as varied as others. I only have about 300,000 miles on two wheels since 2001. I rarely (except on some road trips) ride in dense traffic situations. My commutes back and forth to work were on back roads. But I do ride on interstates, just try and avoid heavy traffic if I can.
Your choice in gear is totally up to you. You know your riding skills, your normal riding environment, the bike your ride, all contribute to your decision on what to wear and when to wear it.
