Self-assured I can say I'm quite a proficient motorbike driver in Asia. I've been driving now for around 4 years with some gaps in between, without a driver's license, in 7 countries in Asia.
Learn on the go as they say. L.O.T.G.
I was impressed by the amount of traffic in Vietnam, Hanoi particularly. To be honest, I was afraid. Sometimes you are forced to drive straight into the traffic. Yes, ghost-driving is part of the game, L.O.T.G. But you can dumb it down to driving around 15-20 km/h and make sure you honk a lot so people take notice and often stop. Mind you, I witnessed about 5 accidents and got out of a few just barely.
In Kathmandu, I was afraid as well. My friends warned me for all the police and I witnessed first hand, corrupt officers, fining her. So I didn't rent one, but my friend let me drive a few times. The greatest hazard in Kathmandu though is the dust and sand. It's everywhere, but mostly in the air, hitting your face, nesting inside your hair and sticking in your throat. A desert isn't much different. So one wears a scarf to protect the mouth, a hat to hide your hair, glasses, but goggles are prefered to prevent being blinded. L.O.T.G.
Yesterday I arrived in Bangkok. Heavily food poisoned with a touch of 'Helio Pylori' - a bacteria that causes stomach ulcers, but I made it out alive of Vietnam. Rented a bike, assuming it's quite a simple drive. In Vietnam, the average speeds were about 25km/h at most. In Bangkok.. well, let's just say that Fast and the Furious was recorded here for a reason and soon I discovered why. Racing around, speeds climb easily to 90+km/h, my adrenaline is pumping through my veins. My girlfriend on the back, who is my GPS (a.k.a. holds the iPhone with maps) and is scared shitless. We have to make razor-quick decisions, while burning asphalt we sort of gracefully arrive.