cockblock for me right now is money. I get freaked out when I take out huge loans and even then I'm in the process of trying to find someone who might be interested in sharing an apartment with me near my university.
My downfall is certainly the lack of personal space. It's difficult to invite a girl over to my place when I don't have a place to offer (due to family rules + sharing room with sibling).
It's my biggest challenge and then after comes the fact that I need to be more independent and take care of myself. It sounds overwhelming for a guy who's had a lot of the chores automated for him.