[tpm2] Lifecycle of handles and contexts

Is there a good resource that describes the lifecycle of handles and contexts, in easy to understand terms?

For example, if I create a primary key and then create a key and seal some data, I can keep unsealing the data without reloading the key. But if I reboot the computer, I have to create the primary key again and reload the key then I can unseal multiple times. So these keys get stored in the TPM until reboot it seems.

Is there a way to flush them out of the TPM or even list what's stored? 

Is there a way to list what's stored, what keys are loaded? What about flushing them out without rebooting?

Thanks!