I definitely need my personal time. Always have, and likely always will. I read, reflect, relax, recharge, ruminate, analyze, and ponder all sorts of things big and small. This time is vital to my existence. When I'm deprived of it for an extended period of time due to other obligations I feel enervated.
I definitely have a higher need for personal time (i.e., being alone) than 90+% of people. I honestly don't mind being in a room or laying on my bed just thinking about stuff for a few hours. In many cases I prefer it to company depending on my mood and my mental needs at the moment, though I am a social person. I also just need time to read, learn, grow, and reflect on things. It's essential.