My cactus is blooming again!

Some years ago – maybe 6 or 7, I was given a small cactus from Arizona. It was given to me in a small pot with a bit of dirt from which it grew. I carefully put it into a larger, old pot and based on past experience, basically set it in a sunny window sill in the office window and ignored it. I planned to water it about 2 or 3 times a year.

It has bloomed a few times. If memory serves me right, the first time it had one bloom. Another time it sprouted two blossoms. Earlier this year, there were 3 flowers on it. When I looked at it just this past Monday, it had 1 bloom and 5 buds! Could that be possible? Today I remembered to check on it again and Voilà, the buds had opened. Here it is in all it's beauty: