The structure too… to… shows undesirable excess and has a kind of negative meaning.
- She was too tired to walk.
- This is too good to be true.
- The coffee is too hot for me to drink.
- The boy has too little intelligence to understand this.
- His behaviour was too impudent for me to tolerate.
- He has become too much of a nuisance to put up with.
‘She was too tired to walk’ means ‘She was so tired that she could not walk’.