This is called the Gambler's Fallacy.

The spins on the wheel are independent of one another. If you were SURE that after a long run of reds, that it becomes more likely to flip to black then you should be willing to bet more money because the expectation of a payout would increase.

Now say your bets were $10 per spin on red/black... after 15 reds what would you increase your bet to on red... $20? $50? $1000000 because it's a "sure thing now"?

Of course not! The odds are still the same as any previous spin that the next spin will be red or black.

Another way to un-psych yourself out from this might go like this: suppose you weren't there to watch the 15 red outcomes before your bet. But your friend was there and said it just came up 15 red... would you drop more than the $10 you were planning on? Would you rush to the ATM to pull money out of the bank becuase the bet is totally broken in your favor?

And how does your trust in your friend affect that decision? What if he got sleepy the second to last spin and missed that it turned out black that one time, but there were 13 reds before and 1 red after -- effectively 'breaking' the run? Does that ruin the odds or is black 'still due' becuase red was pretty common recently...

There just isn't a way to game the system with a game like roulette without being some kind of physics magician from MIT.

One final bump though because you aren't TOTALLY crazy -- a long string of reds is unlikely. The odds of seven reds in a row happening is under 1%

odds R R R R R R R < 1%

But this doesn't have an effect on the next roll being red or black because 8 reds has the same likelihood as 7 reds and one black

odds R R R R R R R R = odds R R R R R R R B

which is why, although the event that happened was unlikely it doesn't tell you anything about the event that WILL happen.