You likely won't hit the same number again
But why? Is it because we are likely to not roll
any two numbers in a row, or is there any other reason? What, in your opinion, makes the appearance of a certain number less likely? The fact that this number was just rolled? There are various ways of generating a random number: measuring the radioactive decay of an atom; measuring the atmospheric noise; measuring other processes which can create sufficient entropy needed to generate a random number. Can you imagine a process(among those used for RNG) where the appearance of a certain number becomes less likely for the reason of its recent appearance?
You actually raise valid concerns
Unsurprisingly, I've been thinking about that too (I guess we, the gambling folks, all have been thinking or feeling something to that tune at some point). The existential question is, well, how random is random? I mean if you see two allegedly random distributions but they are distinctively different from each other, can we actually consider them truly random, or at least one of them as not random?
And that gives you an answer to your questions. If two genuinely random distributions are defiantly different in certain ways, we could in fact draw a valid conclusion that there is some form of "memory" involved in the process, which makes it look like certain numbers are more probable after you roll (e.g. grouping). That's why the casinos should actually be looking for a random distribution that behaves more like a uniform one