First 10k are the hardest but the tail effect of an experienced rider is what gets you. I had crashes in my first 10k but my worst were after riding for decades when I would just randomly hit a tiny oil slick going 70+mph while using zero brakes, zero turning, and zero extra acceleration. Just get thrown low-side due to randomness of having to watch traffic while not noticing a tiny oil slick with enough random variations in the road that it immediately throws the bike when traction regains.