Spills happen in most households and if you have carpet, along with pets or toddlers it is highly likely that you will eventually get a spill of something on the carpet.
Even adults can spill things such as wine or coffee. It only takes a moment of inattention and the deed it done.
It is what happens afterwards that is important. Treating the spill properly will hopefully remove the stain. Simply blotting it will only remove moisture and leave the stain there, so when it is time to move and then when the removalists are gone you will be left with very hard to remove stains.