On mowing actual grass, I love thinking about the algorithm while mowing. Turning(the reduction thereof)is often the most important part. removing awkward corners for later passes is critical.
The other is, if you are like me and don't really have a "lawn" so much as a large yard and a weed season, so just discharge where it lands, is optimizing the discharge path, you don't want to discharge into unmowed grass(it builds up and makes things hard) so the optimal path turns into a spiral, fences also interfere with the discharge, so the optimal spiral is inside out, but you never quite know where the center is so to avoid an awkward edge you go outside in with a reverse path around the fence. and what appear to be inefficient passes(not cutting to full width or doubling a pass) to reduce extra turns into straight lines.
The other is, if you are like me and don't really have a "lawn" so much as a large yard and a weed season, so just discharge where it lands, is optimizing the discharge path, you don't want to discharge into unmowed grass(it builds up and makes things hard) so the optimal path turns into a spiral, fences also interfere with the discharge, so the optimal spiral is inside out, but you never quite know where the center is so to avoid an awkward edge you go outside in with a reverse path around the fence. and what appear to be inefficient passes(not cutting to full width or doubling a pass) to reduce extra turns into straight lines.
There may be a fun idle game in all of this.