Changing careers at 4 years into a job, is it realistic?

After 4 years as a call-centre agent I am thinking about moving into a different field. I have read a lot of threads here and could not find my exact situation. I have good customer skills and I am comfortable with spreadsheets. Has anyone made a similar move?

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.

I took a small pay cut for a year, and it was worth it for the growth afterwards.