To connect with them or have a conversation, either in freindship or romantic interest. I might start with the physical, but what brings depth to the attraction for you?
Certain characters of people are acceptable, great, and maybe even MORTALLY NECESSARY in the personal and impersonal domains.
Other characters are a waste of time all-around, and I can only hope to survive an interaction with them, because they mishandle interactions, or are just too messed up to be a sensible way to spend time.
Unfortunately, someone's complete character is not evident until one has come to learn enough about them, and learning about a person doesn't seem to come until they would comply with any curiosity about their past, or whatever else information is necessary.