Str

I think the point is that in real life if you woke up with a blue tentacle, the most probable theory would be something you failed to consider. The mental motion of taking all the theories that you can imagine, and selecting the one that is most probable given that you woke up with a blue tentacle, is entirely counterproductive, it will give you the wrong answer.

A random person having winked at you is given 10:1 odds of having a crush then shouldn't bob be the same?

No, 10:1 indicates that someone who have a crush on you has 10 times more probability to wink at you. Suppose random person has 1:30 chance of having crush on you. Then, if they wink, they have (1:30)*(10:1) = (1:3) odds of having crush on you. Compare that to Bob, who has 1:5 chance of having crush on you (not 1:30) before he winks, and (1:5)*(10:1) = (2:1) odds after he winks.