All of the following apply:
- I'm fast
- I'm fast, hot and huge
knowledge needed is rather wide, so don't let it stop you.
I think the answer to this is:
the two-character string 'F1'.
The F1 key on a computer keyboard opens the Help system for the active window.
Formula One - also known as F1 - is a high-speed (i.e. fast) motor racing format.
I'm fast, hot and huge
The Rocketdyne F-1 was the rocket engine used to power the Saturn V rocket in the 1960s and 70s. To this day it remains 'the most powerful single combustion chamber liquid-propellant rocket engine ever developed' (Source: Wikipedia). In order for rockets using it to escape Earth's atmosphere, this engine would undeniably have been fast, hot and huge!
Initial attempt for the third part (not the OP's intent): In astronomical nomenclature, 'F1' indicates a specific subclass of 'F-type main sequence star'. Being a star, it is definitely fast (travelling at speeds of hundreds of thousands of miles per hour), hot (with some of these burning balls of gas registering at well over a thousand degrees Celsius), and huge (just look at our own Sun, for example - not directly, though...).