Baby sleep rant

Ughhhhhhh... I'm so tired today. Baby went down at her regular bedtime last night, then woke up at 11pm for no reason and I couldn't get her back to sleep. Usually she can stay awake for a maximum of 3 hours before she gets tired again; not the case last night. She stayed up until 3am. I was so frustrated of trying to help her fall back asleep, so I tried letting her cry it out a few times. She should be able to put herself to sleep now! Nothing did the trick. Finally, she started quieting down and I held her until she fell asleep. This doesn't happen all the time, and i know it probably won't happen again tonight... i just needed to vent.