As nakhui already pointed, speed is relative to the point of observation.
If you live on the bullet (or are the bullet itself), you will notice the rest of the world suddenly acelerating around you to different speeds.
And, more, there's something weird happening when you come close to the light speed, as those simple equations show (for God's sake, simple for Einstein, not for me!!!
).
In fact as a basic effect of the close-to-light-speed the mass of the object observed will tend to reach an infinitive mass value, deforming the space (as the gravity rules said), and then changing the light speed constant and time itself...
A complete mess!!!
As for the second part of your question, a proton have always a mass, even a photon have a mass, the only particle where doubt is remaining about mass presence is the neutrin.
The weird thing (again) is that as you go close to lightspeed the mass will tend to become infinite, (IIRC the change become sensitive above 10% of light speed), so a proton will have a variable mass, but will always have a mass.
The basic problem IMHO is that, being the observer always relative, how the lightspeed can be an absolute??
No clues.
Is that your question???
Ask Stephen Hawkins.
Well maybe he will start with the event horizont, and speed of information, bringing a new level of confusion in your ideas, untill you decide to stop thinking, and go back playing AH.
.....
Ehmm...
What I was talking about??
(note to himself: stop drinking wine during lunch... hic!)
