@Danielle I use receipt apps and submit proof of purchase for most but I don't always and it is nice to know that I can get something back Rather than nothing. But maybe you should learn from that mistake of not keeping your receipts if you're more worried about people "trying to get free stuff" and you not getting more than a few dollars back. I have gotten hundreds on some of these claims just for submitting proof and it's nice having that option, so you should download something like Fetch rewards and that way you have all of your receipts filed just in case:)
Barbie