I don't know if it is my age but I seem to find it difficult to get through books at all over the last few years. But also it's difficult to find those that pitch it at the right level. Not so deep such that it needs one to be studying the subject at Master's level to follow, but not so frivolous that it bores. I've stopped reading a number of books because of that.
Not saying it's either good nor bad but vascop has got me reading (gradually) through "Black Holes, Worm Holes,and Time Machines" by Jim Al-Khalili; and it seems a reasonable book even if, as usual these days, it tends to remind me of things I've read before but forgotten the details of.
I wish I had a better memory; the number of times I need to go back and re-read an explanation of something I know I've read and understood previously, well ..... :-(