There are no such things as "stupid" questions. However if you think your question is a bit stupid, then this is the right place for you to post it. Please stick to easy to-the-point questions that you feel people can answer fast. For long and complicated questions prefer the other forums within the support section. Before you post please read how to get help
Kernel updates are considered "unstable" by Linux Mint, so these updates are hidden by default. You can enable level 4-5 updates in mintUpdate to show them, or use Synaptic to mark all updated packages.
I think it's all right I use Xubuntu with Cinnamon and kernel updates seem to do no harm to my computer. You can lock the kernel package in Synaptic, by choosing linux-generic and select Package -> Lock Version.