Anybody ever done something incredibly stupid as this?

I'm on an exchange in Germany. Today is when Spring Break begins. I was booked to fly to Italy with some friends, but there was some confusion with Ryanair (potentially ubercheap Irish airline) and I missed my flight because I hadn't carefully checked my eticket which is in 24 hr time. I'm from NA so I didn't notice that my flight left in the morning rather than the afternoon. After piecing together ways of meeting up with my friends, it all became too difficult and too expensive. I won't see them for a week and they must think I'm an idiot, which I kinda deserve. I was so excited I didn't think to check if everything was in order. I've wasted over 300 euros on this mistake. I've never in my life done something so careless and had it snowball on me so quickly. So my question is what you read above. I'm not trying to be comforted by other people's misfortune. I'm just asking if stuff like this ever happens to other people.