Just returned from the gym, where my complete lack of upper body strength continually manages to manifest itself in new and humiliating fashions. This prompted me to consider a few things that are, for me, stumbling blocks.
1) Pull ups.
2) Unguarded left turns.
4) Appropriate human social responses.
5) Water conservation (I'm a lengthy showerer).
Of course, the first step to solving a problem is identifying it. Thus, from a certain perspective, I'm on my way to self-improvement. Unfortunately, were there a #6 on that list, it would be an inability to progress any further than a single step on any personal project.