It depends on the person. Me personally, I get extremely comfortable in a relationship. When I’m single, I get really focused on goals. I used to have little to no goals once in a relationship, it’s just too relaxing. The other person can bring food, or you can, just have sex all day, take a day off, go somewhere, you just kind of get lulled into this somewhat hedonistic carefree life.
But when you are single, you sort of shift back into get shit done mode.
Depends on the person(s)(both of you can really get too comfortable in the situation).