Pulling to stand

We lowered Aaron's bed a week ago and guess what we need to lower it again! I walked out from the shower this morning and saw my little guy standing in his crib! It's simply amazing how he can do it by himself. It seems like everything is happening all at once.  Aaron started pulling himself up to his knees last week, then crawling, and then now standing within a week's time.  I am not sure if I should be happy or not when my baby is growing so fast.  Sooner or later I won't be the most important person to him and I will be so heartbroken. :(