What worries me more is that you would think your feelings are over reacting, ridiculous and silly. No ones feelings are as such. Your reaction is completely valid. If you are feeling something it is for a good reason as it is your guts reaction to something and shouldn't be over looked.
Is this a big deal? Well, he hasn't been very tactful in my opinion, but it isn't the end of the world either. I would suggest you tell him so and ask him to be a little more cognisant of your feelings about knowing where the inspiration for thinking of you came from in order to make you feel a bit more special.
I personally don't let on where my inspiration comes from when I talk to both my guys. They are both so different. My husband hardly ever calls or texts during the day and when he does it's more about not forgetting to pick up cat litter or something. I take it as it comes and sometimes add a jokey little thing to my answer, as does he. Mono on the other hand texts me incessantly during all hours of the day
I love that as he sends me all kinds of crazy stuff from pictures to links to jokes. My job is boring most of the time, so the distraction is appreciated. He knows that if I don't return a text, it's because I'm busy and will check in later. Sometimes I send stuff on to my husband and he has no idea that I get it from Mono, all he knows is that I thought of him enjoying it when I sent it.
Come to think of it, most of our daily communication is through our phones...