I went 50cc-125cc then a 350YPVS. The thrill of riding a bike is addictive and enjoyable, nothing accelerates quite the same and you sort of feel that the rest of the world is running at a lower speed to you.
But, not now for me. The simple fact is that a crash in my car dents it, a crash on a bike dents you, crushes you or breaks a bit of you to higher or lower degrees. There are far too many idiots on the road and as much as you can ride defensively (and I still do drive very defensively) you just can't predict everything.
If you he a stationary object at 60mph in a modern car your going to write it off but probably get out, on a bike its not something I want to think about again.
In a car I arrive and get out, on a sunny day in my shorts and tee shirt getting out of an air conditioned environment. On a rainy day you arrive dry, get out and put on your jacket.
On a bike, with all the safety gear (I wince inwardly when I see a guy on a bike wearing shorts and a t-shirt), on a hot day you arrive hot (because your only really cool when running a speed) and when you get off you have a load of heavy and hot expensive gear that you have to walk around in or with. On a rainy day you arrive with a ton of gear on, probably still wet somewhere (normally crotch!) and have to walk round in it or try and get it dry before putting it on again.
Getting through traffic is the only + point on a bike but its one of the most dangerous times, watching out for a lane change or running between two lines of drivers who could do anything (and often do)
If your into it then fair play, I don't think anyone should stop you but there are so many things that are not within your control that can kill or mame you that your taking a sizeable gamble. I've know bike instructors injured, I've known relatives and friends paralysed, I've known friends of friends killed.
Yes, I know car drivers have accidents but out of them all I know, one death (she was texting while going round a corner) and a few injuries.
My brother in law was side swiped by a full length artic that changed lanes over him on the motorway, He was in a punto. He got out the car, you could barely tell his car was a punto but he walked away.