I just bought a new house that was built three months ago. I unfortunately flushed something big down the toilet and had to take the toilet apart, turn it upside down, and fish it out. When I was finished I simply placed the toilet back and bolted it down. Well now my father is telling me you have to replace the bees wax every time you take the toilet off. Is that true? I can't imagine you have to replace the wax if its only three months old.
You only have to replace the wax ring if the toilet leaks. It's wise to replace it whenever you remove the toilet, though. It's not a matter of age, but the fact that a wax ring is intended to be a single-use item. They squish into place when you set a toilet, and that can't happen very well more than once.
It's certainly possible that you achieved a satisfactory seal when you reinstalled the toilet. If you're willing to wait and see, and take the risk of (potentially smelly) water damage to your floor, go with it.