TT's are so weird. It's not helped by everyone there being very strange indeed.
You'll have some old guys who have ridden there at 7mph on an old beater from 1962 with a light off the front of steaming billy and some panniers filled with linseed soaked rags. They'll churn out a 24mph average over 25 miles and then meander back home to their cats and disabled wife.
There will be a load of massively serious blokes on single speed TT bikes that sound like a bucket full of bottle caps falling down some stairs when they pass you from ten minutes back. Those are the guys who will put in the fast times. They have this 1000 yard stare *all the time* and the only time they ride a bike is in the TT.
Then there's your common TT stalwart who is just a bit crap, rolls along at 18mph in these horrible cruddy bibs which he never washes.
There's the people having a laugh on a tandem or a mountain bike and finally you have the guys who turn up for two or three TT's on a normal racer who simply haven't got the mental blocks missing that allows them to apply 100% power, 100% of the time (and yes, that's me)