What is going on?!

So Brett will be 1 1/2 years on Nov 1st. God. We are into full blown toddler-hood. We have the meltdowns, the occasional tratrums and the pickiness when it comes to eating; something that I have never dealt with before with Brett. But, there is another thing. Something that has driven Nic and I CRAZY this past month. I have no clue why he is doing it, but I am about to loose my mind. Awakefullness. Is that even a word? Well, in our household it is! I thought the first couple of nights I could blame his waking up at 2AM due to molars-he is getting two on top the exact same time. So I tried Tyelonol. Didn't work. Then I went to my moms message board and begged for help. They told me to try Mortrain-it lasts longer than Tyelnol I guess. Worked one night. They also suggested teething tablets. Again, one night it worked. Now, Brett will usually wake up around 2ish, sometimes crying,sometimes laughing. I hate to pick him up because then he will get the message that it is OK to wake mommy and daddy up all the time. We have tried the "cry-it-out method, only to have Brett crying hysterically, along with myself. I have taken him the the doctors only to find out that nothing is wrong. It is a total hit-or-miss. One night will be good, followed by 2 night s of hell. I should add, when he does wake up and doesn't go back to sleep right away, he wants to play and NOTHING will make him go to sleep. I have had nights where it is 4AM and he finally decides to sleep. I just can't for the life of me understand what is going through his cute little brain. he has NEVER EVER had sleep issues before. It started at 17 months and we are almost into 18. Mommy can't take much more!!!! But, all in all, he is a blessing to our lives. I mean, who can resist this adorable face? (Well, I can at 2AM)