Wracking my brain

I'm staring at the plants and can't remember their name.  And my husband had just mentioned them a few hours earlier.  Hostas, that's it.  I have trouble retrieving names of other trees and shrubs around our yard--the magnolia; the crape myrtle.  Is this natural aging, or something worse?  I've started looking in the yard and repeating the names so I can remember them.  Yet I was watching a movie the other night, heard a voice I recognized, and realized it was Hugh Beaumont, who played Beaver's father.  Why do some obscure pieces of information come readily, while I struggle for others?  Especially labels for things.  I have to work at remember people's names, but that's a longer-standing issue.  I'm much better at remembering voices than faces.  But naming objects seems like it may be getting more difficult.  Guess I should monitor and observe.