potty training

I have been trying my hardest to get Conner potty trained for awhile and although he understands it.. He is very strong willed and stubborn. I have put him in underwear a couple times to help he realize that if he pooped or peed in there, that it would be a yucky feeling. Well he did both in his underwear and it didnt bother him one bit. He just seemed to keep playing. I could just imagine Conner asking me the same reasons as the Cartoon above of what the importance of Potty training really is.. Because Right now he does not get it! Although Yesterday he went was Dry after Lunch so I sat him on the potty, went to help Nolan a little boy I watch get in bed and right as I come back into the room I notice that Conner is going potty. He was soooooooo Excited and so was I. I decided to put him in a pull up and he went again after nap and after being dry. He didnt go the rest of the day yesterday but he did get a start so I was excited about that. I mean he is 3.. And diapers are getting tiresome and expensive. Of course today he has no interest in it but I just have to keep trying and not be lazy myself. He will get it soon. I never met a child that was never potty trained. So Iam hoping for the best. I just need to be patience.. hopefully I won't have to be patient for two long :)