You're right. Awesome ideas should be credited - especially if you then go on to use the awesome idea.

Credit where credit's due.

Sometimes, an idea can be spotted, read, absorbed and then is set off inside the mind of that reader and it's not until later that a new awesome idea comes from that first one.

Sometimes, you can genuinely forget where you saw the inspiration and that's a sad fact of our very human brains, we do forget.

If I've ever done that, I'm genuinely sorry, I do always try to give credit... but my mind... when it latches onto something, it can keep hold of it for a while and not spit it out again for months.

Good Luck! and keep coming up with those awesome ideas. You have the advantage, those that can only copy you have to wait for you to come up with the next new thing.