You always leave a gap do you? The evidence says otherwise! You try to undertake when, by your own admission, his/her actions are predictable. You followed the driver around the roundabout to the point where his/her intention is fairly likely to be to leave at that exit, but your own spectacular failure to read the situation is supressed by your moronic instinct to attempt an impatient undertake.
I was wondering why my kebab was taking so long