Parties still rock on the weekends

Could someone explain how come bars are so awesome on thursdays and yet they suck both on fridays and saturdays; there's no one there! actually house parties are way more of a blast: there is people, there is booze, and its cheap! I understand that bars like cactus moons are only good on wednesdays because of their themes on other nights but all the bars on 4th av or university just do not fill up and therefore the environment resembles that of a town in the middle of northern Nebraska. Hopefully we get something going in the upcoming weekends!