When no Bitcoins are left to be mined, how will the Blockchain continue to be validated? Sorry, this may be noobily phrased.
My understanding was that each individual "miner" crosschecks and validates the overall blockchain, ensuring decentralized verification of the bitcoin transactions. The reward for devoting your processing power to this verification system is newly "min(t)ed" Bitcoins.

So, I'm wondering, when there are no Bitcoins left, as in it reaches 21 million (out of the ~15 million in circulation now), how will the blockchain transaction system be validated any more? As in, the reward incentive of getting a piece of newly hashed Bitcoins will be gone, so nobody would mine any more?

I figure there's something I'm missing, but from my limited understanding it sounds like the verification backbone of Bitcoin will be in trouble. I assume there's existing threads on this topic, I just am having trouble phrasing my question, so it's hard to search
Mining rewards are not the only source of income for miners. There are also transaction fees. When there are no more bitcoins to be mined (happens around 2140) then miners would be mining for transaction fees only.