Why are you wary of using something like that? I use one of them, and it has been a great help for me for studying and for work. I don't take them during "off-

Why are you wary of using something like that? I use one of them, and it has been a great help for me for studying and for work. I don't take them during "off-time", i.e., weekends and holidays, and I don't feel like I need them for my hobbies, where part of what makes it fun for me is that I can take my time, shift my focus constantly, and define "progress" by my own internal metrics.