I have not done much motorized dirt bike riding even though I did briefly own a Yamaha 360 Enduro back in the day!
But I did ride with a group of crazy road bike riders (pedal bikes), and I've done 59 MPH on my bike (on the downhill) and slalomed down long windy downhills (after climbing up them) at 40-50 MPH only inches away from other riders. If you watch competitions like the Tour De France and don't understand the importance of drafting, you will if you ever ride with a group.
Let me tell you, you had better be on your game doing that! My road bike is Carbon (as are the wheels), the tires are inflated to 120 lbs and are only about an inch wide (actually 23mm is only .9 inch wide), there is no suspension, and it has pincher cork brake pads (discs on road bikes came out later, and they have cork instead of rubber because the rubber will make a carbon wheel so hot the tire will blow).
In addition to having riding skills, you must avoid any potholes, stones, branches, and animals (squirrels, wood chucks, cats, foxes, deer, and even a bear). And I did not even mention the cars (3 times I've had stuff thrown at me from moving cars).
I've witnessed a few crashes, but luckily the injuries were never as bad as they could have been (road rash instead of broken bones). The scariest was when a guy braked hard on a steep downhill curve and his wheel folded and he went across the road just barely being missed by a car coming from the opposite direction. Luckily, the car driver braked hard and fast, but I always replay that one in my mind any time I'm thinking of taking too much risk.
Another time a deer ran out from behind a solid fence and our lead rider hit is so hard that the bike cartwheeled over the front wheel. He tucked, but had the wind knocked out of him when he landed, and he stayed on the pavement for about 10 minutes. An ambulance crew arrived, checked him out, applied a few bandages and he rode home!
I've gone down several times when mountain biking, but never when road biking. Age and injuries have taken their toll, so almost all my rides now are solo, but I do miss the good old days. We used to ride 4 days a week, 25-35 miles on weekdays and 50-75 miles on Sunday. Often the group was 6-8 riders, but on a few occasions, we had 18 riders (which was really too many).