guilt surrounding parents paying for things as an adult

context: i am 22, and i moved out of state for my first job post-grad last August. My parents still pay for my phone bill, car insurance, and netflix.

since i moved out, i honestly have been pretty good at saving money. i budget to the cent, i am decent at saving (i love coupons), and i rarely spend money things that aren't groceries, rent, or small hobby-related items (yarn for crocheting). However, January was a really hard month and I ended up having to dip in to my savings due to having to update my vision prescription in my glasses and get my car serviced.

i talk regularly with my parents, and when i mentioned the prices of the glasses and the car service, they offered to pay for both with no strings attached. i took up their offer, but i feel so so so guilty. i definitely had enough savings to cover both items, i was just annoyed about having to do it. i saved up money for things like this, but also i am very glad that they offered to pay. but i just feel so guilty. is this normal? should i offer to pay them back? they know that i could have paid for them. also, they already have helped me out so much, and they still pay for my phone and car insurance.

is it okay that my parents paid for these?