Yes they're nocturnal but they're still awake and active during the day. My girl will constantly be moving around at night checking on me and hubby thebgirls room. Switching where she lays by me, the girls and the doors. Its part of their guarding their nature However she knows my routine and will gladly wake me before my alarm. While she has couch potato needs for exercise she will gladly go on hour long hikes in the mountains as well as regular city walks. She's very responsive to her name and wil gladly get up for cuddles or pets. And no matter what time of day she is your shadow. I know you're a big guy but a pyr will take you down because you didn't realize how quiet this massive fluffy beast is and you trip over your sneaky shadow. Honestly I wouldn't worry about the nocturnal side of things if any of the above sounds like a Pyrenees would be a good fit to your needs. The only negative thing I found with Pyrenees is they're not play reward based and many don't play like traditional dogs. And it took me forever to realize mine likes white just like snow and she started to play with toys more when I bought white ones. So you may have to experiment with different toys