And it's good.
The fear comes from the fact that moving from an MTB to a track bike and a road bike means the machines I am riding now are much less stable than the one I have been riding for a couple of years.
I'm not sure which is scariest. The track bike is hard to handle on the bends. The wheels wobble and I fight to control it. Of course there is also the issue of it being a fixie, with no brakes! About once a session I forget I cannot freewheel and have an exquisite moment of panic. Then there's the practice racing (at which I suck mightily, boy am I slow!) during which I feel like I will touch wheels with someone and die.
The road is also scary. I never realised roads are full of so many tyre-wide nanogorges, waiting to throw off a road bike rider. I'm also learning more every day about my bike's turning circle (or lack thereof), which makes for some interesting moments on tight turns. At the top of the list is the cleat/shoe thing, which I still manage to get panicked about once or twice per ride as I slow down to a point at which I reckon I'll be able to click out, then can't manage for half a second or so. I fell over onto the road the first time I road the bike and have no desire to do it again, but suspect there is another in my future.
The fun part about all this fear is that it shows how much I have to learn. "Just like riding a bike" is an old cliche. Who'd have thought I have so much more to learn about something I have been doing for so long?