I think I'm pretty generous with bad first impressions. They make for great stories later on if your relationship survives.
Kady of a lady reveals nothing and I had been aware of one another's existence for several years before we were formally introduced by two mutual parent-figure friends. Kady was headed to China and I to Eastern Europe and they thought we needed to meet one another. Our exchange went like this:
Kady: So you're going all by yourself? Where are you going to stay?
Summer: I guess hostels for the most part
Kady: Be sure... that you... make sure that you don't... let people... rape you or murder you.
I thought the chick was nuts.
Years later, I found out that her advice was armed with knowledge of this recently released horror film based on the premise of sick sadists purchasing travelers from hostels in order to "torture, punish or murder them." The truth is "don't let people murder you" is pretty good advice, which I have, as you can tell, thus far applied.
And our friendship has survived. As you can tell.