I remember thinking how crazy my SIL must be when she told me how she used to relish going to the grocery store by herself. I blamed it on her triplets and thought I would never get to that point with only one (maybe another down the road, but let's not get ahead of ourselves here). Then one Saturday morning, I realized that I had spent two hours grocery shopping while my husband stayed home with our son. I called my SIL from the car and said, OMG, I'm there. I was so desparate for me time (and unwiling to selfishly take it) that I just spent two hours leisurely doing something I used to rush through, unconsciously forcing "me time" with the inanimate objects at the grocery store.
Since then I've tried to take me time when I can, but it's so hard with work and life constantly getting in the way. But when I take it, it's usually for something regenerative, like yoga or a massage.