Here are my personal 10 commandments in this hobby:
1. Don't say anything about their sound system you wouldn't want them to say about yours.
2. If you have to criticze, say it to yourself. You might survive longer criticizing his wife than his sound system.
3. If in doubt, don't buy. Check the net. If still in doubt, trust your ears.
4. If you can't trust your ears, get another hobby.
5. Never compare; the other man's grass is always greener.
6. Never ask a salesman for his opinion, he's reliable only when asked How Much.
7. This hobby is supposed to be fun. If you can't have fun, time to upgrade.
8. If your wife can't stand your hobby, time to change (whichever I leave to you)
9. If they like what they hear, offer them your gears at cost, so you can upgrade.
10 Always buy in pairs. For every gear, a present for the wife.
Care to be more serious???