If you do get a puncture (and we all have had one or will have one) be sure to properly check the outside as well as the inside of the tyre.
The other day I was unfortuneate to get a puncture. My own fault, I never looked where I was stopping and parked up on a piece of glass. As I remounted the bike the glass instantly cut into the tyre and that was it 'FLAT'.
I stripped down the tyre, ran my fingers around inside the tyre and found no protrusions so made good the repair. Pumped up to half pressure and rode to the nearest filling station to inflate tyre to full pressure.
Two hours later - another flat. Fortunately for me I am wise enough to mark, with chalk, the outside of the tyre where the punture occurs so I can check back later if I need too. On this occasion I could find no reason for the puncture, but it was directly where the chalk mark was from the previous one. After much searching and rubbing off fingers, flexing of tyre, ect, ect. I found that the original punture had cut one of the wire threads in the tyre. It was the cut end that had caused the second flat. To make good I just pulled the whole thread out of the tyre. All has been good since.
So, just because you think you have got it the first time I now advise that a GOOD thorough check of the tyre both outside and inside will save a lot of time and work. Always mark the tyre where your original puncture was too. This could save much head scratching later.
Take care and ride Safe.