To me there is nothing to regret about because gambling is totally a game of luck so your winning will not be tired to the numbers because whether you change number or not when it your day you're definitely going to win your ability to see gambling as it is , is very important because it will help you not to kill yourself about gambling too much
To be strictly fair, there is a high tendency of catching regret. Changing up the set you bet regularly afterwards that number won, tell me you won't question yourself?
Having regret in gambling isn't a bad habit for me, what action you take during regretful moment is what should be looked into. Not going far into lottery, just the way we have Bitcoin raffle in the forum, i basically have my favorite number i choose once its vacant, if someday i don't pick the number while meeting it vacant only for the number to come up as a winner, i will instantly become troubled for not picking that particular number.