The example you gave reminds me of a similar conversation we've had about phrasing constructive comments on this site ;)
I'm heading out shortly and your car is blocking the drive.
This is a statement of fact. OK, so what?
You'll need to move it out onto the road. If you don't I can't get my car out.
Aha - they want you to do something about it!
It may seem super obvious to you why they said the first part, but it's not always so. Even (especially?) in relationships, you see the following happen: Person A makes a statement, expecting Person B to understand and fulfill the implied request. Person B doesn't realize this and doesn't do the request. Person A gets upset that they didn't do it. Person B gets upset because "I'm not a mind reader!".
Many of us (myself included) have had this experience, so we've found it beneficial to be very clear in our communication. If I want my partner to do the laundry, I don't say "hmm, the laundry basket is getting pretty full", because he's just as likely to say "yep, sure is" and move on, and when I get home from work I'm disappointed that the basket is still full of dirty clothes. Instead, I say "Hey, could you do the laundry today?", making an explicit request (so then he responds yes or no, and there's no surprises when I get home).
Another possible reason, like when your colleague mentioned turning on the printer, is that they have experienced those problems before or seen others tripped up by that, and are trying to save you the trouble. If my coworkers mention a problem that I've dealt with before, I often ask them some basic questions to get to the root of the problem - sometimes even though they're quite experienced and competent, we all overlook things sometimes. As a programmer I do this more often than I like admit - so when a coworker says "you're sure you're compiling the right code, right?", I know they're asking because we've all done that before!
So that all is to say, it doesn't sound like people are necessarily saying this out of disdain for you or because they think you're stupid, it's that they're trying to be helpful and clear in their communication. Even if they might not be, it's best to assume good faith in your interactions with others until proven otherwise.
How do I kindly explain to these people that I get it, I honestly have thought of whatever they are about to say, but in a way that doesn't deter them for contributing useful observations in the future?
Simple responses like "yep!" or "thanks!" are a good way to acknowledge politely. If you were already about to do whatever they suggested, "Yep, already tried that" or "Yep, on it!" conveys that, without getting into details. I do this with my mother in law, who is a bit "Type A" and just likes to give advice. She means well, and I don't want to risk conflict, so my priority is to be appreciative of that over asserting my expertise. (Although gentle humor, if you can pull it off, can work well, e.g. "no worries, I haven't burnt down the house yet!")
Another option is to explain what you have done or thought of, either before or after the comment. Over time they'll learn the extents of your knowledge and realize they don't need to remind you of the basics (if they pay attention, that is.. unfortunately that bit is mostly up to them!). I've had to deal with that starting new jobs before, where it took some time to "prove myself" before the new coworkers figured out what I was experienced with (or not).
In addition, make sure you're modeling the behavior you want to see. For instance, I often preface my basic-level suggestions to coworkers with "This may seem obvious, but have you tried...?". Although it's not direct, they may pick up on these mannerisms and reflect them back to you. It also makes it easier, if this becomes a long-term problem with some people, to discuss your frustration if you're not doing similar things yourself.
In all of this, keep a friendly attitude! If they are hurt by your response, they will be less likely to volunteer information in the future, for fear of another bad response. This goes along with assuming good faith. Thank them for their willingness to help you out, even if it's the most obvious thing in the world to you and you already knew it, so they are encouraged to continue contributing in the future.