Girls: if you say a guy is complex, what does that typically entail?

Recently I have been doing some research for one of my cles and on-going projects at university and I sent out a johari window application for people to fill out. Basically, they have to pick five or six adjectives out of a list of sixty or seventy to describe me. So far I have gotten ten sets of adjectives, and two of those sets included the word "complex" to describe me. I guess what I am wondering is, from a girl's perspective what does 'complex' entail? I ask because this isn't the first time I have heard this word used to describe me, and I've always wondered exactly what it means. I'm just interested in hearing a few takes on it. Any ideas?