To feel so unemotional?

I find it difficult to think of any occasion in my life when I've genuinely experienced intense emotions. I've felt excitement sometimes, but when the thing I'm looking forward to actually happens, I return to my normal state. I've never once lost my temper, and even when something important happens like failing my exams I find it difficult to care.

When I hear how other people experience life, I find it difficult to emphasise and often feel I'm missing out on something. I'm more into reading than the average person, but when they talk about books they like they go on about how they 'couldn't put it down' or 'couldn't stop crying at x', while the most I can say for even my favourite books is 'I enjoyed it'. I get the same way when watching sad films or reading about something sad in the news: occasionally I'm affected for an hour or so but nothing seems to have the same kind of impact on me that it would on other people. Over the past few years this flatness has gotten even worse. I could imagine responding strongly to something really dramatic, such as a close friend dying, but for the most part everything seems the same. Is there anything that can be done to change this? I've wondered about depression, but my whole life seems to have been like this.