There is no action of "commiting to memory". It's not an action we do, it's a process that results in that.
The actual action we do (when we consciously try to remember something) is e.g. to read, repeat, and so on.
Mental notes are a pretty commonly known concept; not that I'm claiming everyone can make them easily, or at all, but they don't typically require focused studying. I'd consider them an example of committing something to memory intentionally. Sure, studying is another way of committing things to memory. You can read something repeatedly and completely ignore it just as much as you can read something repeatedly with the intention of remembering it. You can also make mental remarks without them becoming mental notes. But it is certainly possible to create a memory on purpose. It's just that studying an entire subject requires you to train your understanding quite a bit in order to build a good memory of it, as opposed to memorizing a single simple idea or lesson that you already intuitively understand.
A good example of committing something to memory on demand is making a mental note. I don't know if everyone has this ability, but it's a pretty commonly known concept. You don't have to study the subject of the note in order to remember it; it's often something simple like "do this tomorrow" that you already understand, so it's easy to memorize.
To memorize means to commit to memory. It is an action. But memories are created by not just actions, but experiences. Experiences can create memories without you having committed them; without you having memorized anything.