Investment in writing can be huge. We’re not talking cash, we’re talking time, creativity, emotion, thought. I (Loz) cannot be the first person who has wept while writing a scene a character who has lived in the corner of your brain for years finds painful. Every writer invests a little tiny bit (or a big bit, it can depend on many factors) into what they create, as do musicians, artists and photographers. To be truly creative is to invest your passion into what you do, so make sure you invest wisely and fairly, but don’t be too angry at yourself if you invest foolishly every now and then.
There is also the readers’ investment. As writers, we want our readers to be as invested as us in these characters we have created and fleshed out. We want them to feel for them and their situation, to care if they live or die.. or get hurt every now and then.