You definitely need time to devote to work: there's no doubt about it. You could end up doing some unexpected overtime for the next day or so, thanks to someone else's willingness to blow off their own workload. You're also feeling the urge: and it's a strong one: to be alone, even if it's just for a little while. Well, that's what evenings are all about. These urges might start later this week, but they'll still be there.