The Opposite of Play isn't Work. It's Depression.
Unless your battling depression, when you're doing it right Work, Play, Life, are all the same thing.
I don't get people talking about "work/life balance". If it were a Venn diagram, 'Work' would be entirely inside Life. You can't have Work without Life. I'm not obtuse here - there's plenty who try to make the work take up as much of life as possible, but by virtue of their relationship, Life is the priority. To hijack Brian's quote: the opposite of Life isn't Work, it's Death.
Ultimately, I'm advocating for more Play. Play is what blurs the lines around Work. With enough Play, the lines become invisible, and you're just left with Life. It's okay to be silly at work. It's okay to be yourself.
If you see Work and Life as two separate things, it means you're living two separate lives. That means you're doing even more work to maintain that.
That seems exhausting to me.