If you go into your power settings in control panel and then Advanced settings, you may see that your laptop is set to go from Sleep to Hibernate after a certain period of time when you close the lid.

I have disabled ever going into Hibernate because it takes longer, much longer, to come out of hibernation that it would have taken to do a complete boot had I shut the system down. So now, when I close the lid, it just goes to sleep and wakes up right away when I reopen the lid. I would advise though, to save / close your programs when putting it in sleep mode if you are walking around or moving/driving with the PC in sleep. Hibernate saves your data before going into that state. Sleep doesn't.

I drive around all day in a sales job and close my lid to put my tx2 in sleep state. The laptop wakes up right away when I need to do a demo of my business applications.