Miseries of the end of the month

"See you tomorrow", a colleague said as I was leaving the building. "If I am still alive" I answered. It is not very original, but in the context I think it qualifies as a great unknown line. It was such a long, exhausting day. The end of the month is always a busy time, but more so when the week is at its peak, like on... a Thursday. I am tired, I feel like I have been running all day, I barely have the energy to focus on anything. So I am rambling. Am I the only one who feels like this on a Thursday when it is the end of the month? I should be satisfied: I got paid, I made money, I mean I didn't work for nothing today, it was not a frustrating exhaustion. But i just feel tired. So anybody else feels like this?