There are things one encounters head on while riding a motorcycle or scooter. Bugs, rocks, cigarette butts (still aflame mind you), and various and sundry other objects and debris. For this reason, I have found a full face helmet with a shield is invaluable.
There was another discovery I made on one of those adventures; hail hurts! The most recent storm I endured (see video) included these lovely little balls of ice pelting down amidst the heaviest rain in which I've ever ridden. The rain was so heavy, my Frogg Toggs jacket was quickly penetrated by the deluge and rendered completely useless. By the time I arrived at home, my clothing was thoroughly drenched, even my shirt, so I just stripped it all off and threw it in the washing machine. Even so, I felt invigorated! It was one of the most exciting rides of my life!
Getting back to the topic of bugs and other debris, wearing a helmet with a full face shield quickly reveals what kinds of things will hit a rider in the face. The above image shows some insect remains, but can't show the other things that might come flying at a rider. Just this week, a driver in a 5 series BMW decided his lit cigarette butt belonged in my face; my helmet prevented this. I have no issue with people smoking so long as they're polite about it: i.e., don't smoke in doorways I have to walk through, don't blow smoke in my face, and don't throw your cigarette butts at me.
Riding motorcycles and scooters can be great fun, but it can be hazardous too. I've not been riding as long as some, but in my brief time in the saddle, I've found that the pleasures of the ride can be ruined by little turns of events, but proper gear can lessen those effects. Yes, it doesn't solve every problem, and even the best gear has its limits, as my experience with the Frogg Toggs jacket proves, but it makes a difference. In point of fact, my son used the same jacket today in a moderate rain and it worked very well.
So ride safe, take precautions, and have fun. The rain may fall, but you don't have to stop riding.