Usually I only buy fabric with a specific project in mind. Occasionally I just can't leave some fabric/pre-cuts behind because I fall in love with them. Those are the ones that haunt me because I sit for months looking at them and have no idea what to do with hit. I held a Swirl JR for months then the falling charms quilt tutorial came out and it was still a month or more before I decided to use that JR for that quilt. When I fall for a pattern it makes it a lot easier to use that and go buy fabric/precuts with a finished project in mind.
You are not alone.
I am like you Lisa...however, when I buy material I usually end up buying more than I need because I love it! Crazy I know! I rarely buy precuts, I prefer having that large piece of material.