That's because you are most likely seated too low.
Nope, as all modern jets we do have those nice little ball thingies giving you the exactly correct eye height (in my case: Airbus).
Look (litteraly), a human brain is simpy not able to judge attitude to the last degree. In a long wide body jet aircraft, the difference between 10 and 11° is in the air or tail in the tarmac. Look at the skidmarks in Melbourne...
btw you don't see the nose if you are seated correctly in an Airbus, and I think to remember the same is valid for most other jets - except the Concorde with nose not lowered.
May I ask what type you're flying?
Even during landing we have to check our primary flight display. You simply cannot make a landing purely by feel and luck.
Dani