Characters & Experience
Question: I feel like I have a lot of cool ideas and concepts for a novel, but they are way too big for me. I wouldn't be able to empathize with what the characters are going through because I haven't experienced enough. Is there any way around this or is this really a matter of just experience and maturity?
There are two main tools you have to balance: research and imagination.
You can fill in many of the gaps in your knowledge with research (either reading about a variety of other people's experiences or perhaps talking to people who have had experiences similar to what you want your character to undergo). Most novelists will do a certain amount of research on settings they want to use, topics their characters know about, things they want their characters to do, etc.
A strong imagination can fill in many of the remaining gaps. This is similar to how the human brain fills in the blind spots in our vision by extrapolating from what it can see and what it knows. You can take experiences you've had that are similar and extrapolate from them to imagine what an experience will be like for your character. Combined with research, imagination can take you a long way.
The other thing that helps is the fact that human beings have a lot of similarities. If you know a lot about your character, and you are an empathetic person, asking yourself "How would I react if I were them in that situation?" can help you figure out how they would respond.
For this reason, a lot of writers feel that every character they write is simply a facet of themselves--themselves in different shoes, as it were.
In fact, research can never tell you everything you need to know. You always have some gaps to fill in with imagination. After all, you're writing about the experience of a unique fictional character, not any of the real people you may have talked to. Your character may respond differently to the situation than anyone else, so there is a point where research will fail and imagination must take over.
On the other hand, you can also get in trouble if you rely too much on your imagination. If you are lazy when it comes to research, you may not have enough information for your imagination to work with. You may not be able to fill in all the holes in your experience in a believable way, so that you end up with a story that feels inauthentic, especially to any reader who has firsthand experience with the subject matter. For this reason, writers are often told, "write what you know." When you have actually experienced something firsthand, you are better equipped to present accurate and authentic details.
That said all writers write about things they have not done themselves. No writer can pursue every career their characters do, or visit every place on the globe (let alone fantasy worlds), or master every skill their characters must possess. So, although being a brain surgeon would help you to write an authentic story about a brain surgeon, it's not a requirement.