Not to be boastful, I have to say I earn enough that I could make a living from it (I am from the UK), but there are significant monthly costs (mostly paying for quality content which doesn't come cheap with the writers I use). At first I use to write a lot of the content myself but now prefer to do the admin work while outsourcing the content to writers.
I have a job and that keeps me sane. Since I now outsource all the content needs, I would have way too much time on my hands (if I didn't work) and would drive me crazy from not knowing how to utilise it.
During summer holidays I will probably end up going for walks in the park everyday and then going from one cafe to the next sipping tea and coffee to pass time, and while there, logging on to adsense to check stats.
Sometimes I feel my life revolves around adsense. I even log on to adsense quite a few times from work. I think this stems from the desire of owning a very substantial site that you can be proud of so you can prove to yourself and others that you've accomplished something. But it can get dreary.