Muscle or fiber?

I know a guy (male - 30 years) gets its showing Arnold, or almost. Has a body with muscles all went well in relief. And sometimes somewhat jealous of him, but not always.
It 'working' muscles at the gym, and shoot the 'beast' in a certain way, not in despair, but everything scheduled. Today do exercises for biceps and abdomen, and legs tomorrow for ....... because I did not understand very well, no I did not bother to understand. The idea is that I asked:
-If I join the gym after a year of training so I can have muscles?

But he gave me an answer that I did not bode well at all:
-Nothing hitting the weights if you do not follow a diet and not exactly help the body with creatine and some other substances.

Terrible! To stick in me all kinds of chemicals?
One day I was at a buddy to help him to discharge a cement truck, because that friend was to pour some concrete in the front yard of the house. And believe? He with his tired muscles in the middle of the truck, and I Arnold man without muscles I did the challenge with flying colors. Why? For that I'm 'playing' with difficulties, not the gym but at home, but I do it naturally, without chemicals, proteins, and other stuff, I do not fiber mass and fiber mass beat.