Alone by himself

Luke 9:18a Now it happened that as he was praying alone, the disciples were with him. (ESV)

I need to be careful not to read too much into this seeming oxymoron. Although some other versions of the Bible agree with this rendition, others say something like "the disciples came to him," or imply that they were praying, too. But I remember that they went to sleep when He was praying in the Garden of Gethsemane, and I don't recall any time (except this one) when Jesus and the disciples prayed together. It was always Jesus alone.

Let's assume that the passage means what it seems to say. It might have, I guess. How many times would Jesus have prayed, and wanted me to do so, too, when I was busy doing my own thing?

Thanks for reading.