Wow, that was some pretty clueless advice. Everything you just said is wrong.
1. Aim where he is, on LAN. CSS has terrible netcode and hit reg, which is a big reason why a lot of people stayed with CS. In theory though, aim where they are.
2. As a CT you will spend a vast amount of your time staying in a relatively small area, or standing still. Equally, you will as a T once you've planted, most of the time anyhow. CS is more about positioning than it is anything else, and learning where to expect people, how to catch them out and so on with your own position is 90% of the game. There are exceptions to this of course, but as a rule - If you're not 'camping' as a CT, you're doing something wrong.