I worked retail for many years, and we had plenty of customers who would do what we called "recreational shopping". These are ladies who come in every week, spend tons of time trying on clothes and usually purchasing quite a bit. The following week they'd be back and return everything, usually going to a different part of the store for the returns so they didn't have to face their original clerk.
It was sometimes frustrating, as we worked on commission, and some salespeople felt these customers were time wasters. I never felt that way, and was happy to help. Keep in mind these women would come in every week, and spend at least an hour with a salesperson.
The most prevalent "over-buyers" occur when there's a "ladies night out" and we'd have 3 or 4 gals together who'd be shopping after a nice dinner together. I know they'd all probably buy a bit more than they wanted to, and I was always happy when they'd come back a few days later and return the items because then I felt they had the fun of shopping without breaking the bank. None of the other salespeople I worked with EVER had negative things to say about this kind of shopper.
Sounds like you're in this last category - if these are items that you won't use, or they're not in your budget, return them without worry - no one will judge you!