Lighting circuit layout

As a result of the dry rot we had recently we had to take some ceilings down which has exposed the electrics. It all looks pretty good considering - all pvc and T+E so I'm really pleased I don't have to get that sorted as well.

But, what I did notice was the upstairs lighting circuit is not a simple serial. It looks a bit like the diag below where CU= Consumer unit and L1= light 1 etc.

From my memory of physics i cant see it's an issue, but should I consider doing anything about it?

Perfectly normal. It is a radial circuit and you can have many branches and cul-de-sacs.

The main thing to look out for is if the circuit is sufficient for the total load!

That is absolutely fine, and not particularly uncommon.

Have a beer and chill.

Thanks, I could see why it would be an issue, but always worth checking with the experts.

Just counted up 900watts and the cable is 1.5 T+E so should be fine and dandy