Bear with me for a moment as I state the obvious: A generally understood idea about work is that it's not always fun. That's kinda why people pay you to do it. If everything about it was totally awesome, they'd do it themselves, or people would do it for free, or they would pay to do the "job." Basically, if your job was all-fun, it would be a pizza party, not a job. That said, as a working mom, there are times when I love working and find work to be downright blissful, like it's the third best thing ever (after my family and pizza parties, obviously). That puts it ahead of coffee, ultra-fine point Sharpies, and fluffy infinity scarves, which are my kryptonite. But I stand by this ranking: Jobs are frequently amazing, and being a working mom is kinda the best sometimes.
OK, yes, it probably helps that I have a job and a work environment that I love, and I know that so, so many people don't have the luxury of working in a field they love, or doing a job that brings them very much satisfaction at all, but trust me, loving my job has not always been the case, so internet hugs to anyone currently fighting that battle. Still, I would venture to say that even when your day doesn't float your boat, there are some universal things about having a grown-up J-O-B that still apply.
I still struggle with working mom guilt on the regular, but I try not to let that get in the way of enjoying parts of it. When my son is old enough, I hope he'll understand how my work stretches a mental muscle that my family responsibilities don't, and the fact that both of his parents are creatively fulfilled is better for all of us, including (especially, actually) him.
Here are some little pleasures of being a working mom that no one else gets to enjoy: