I totally just changed my doorbell because of this thread.

Considering I made the majority of my rookie mistakes playing the Sims 2 (i.e., not knowing how to feed my sim, not putting doors on houses, etc...) when I got the Sims 3 I actually decided to read the manual back to back, lol.
Nevertheless, I had no idea how to get a romantic relationship. I asked a sim to move in with mine, and they were living together for quite a while before I realized there was a "Romantic..." option.