Seeing someone about 18 years later

Yesterday, I went to a school in the district to show a slideshow on the last day of summer school.  The person who normally works in summer school could not be there.  They wanted me to fill in.  While in the library showing the slideshow to one of the classes, I see someone that looks familiar and stare at her (not for a long time or in a creepy way, I swear!).  She looks at me and we say nothing to each other.  Towards the end of the morning, she sees me again and says, "I think I know you.  Are you Shane or (my brother's name)."  I said, "I'm Shane.  Are you (The correct person's name)."  It turns out we both knew each other.  She was my second grade teacher!  I find it absolutely amazing that teachers can remember students they had 15 plus years later.  They have had hundreds of students and still recognize you.  It's crazy!  You would think that since I have grown so much (taller and wider) that she wouldn't recognize me.  I can't see myself recognizing students years from now.  Who knows?  Also, this teacher is only a substitute now because she took time off to have kids.  She is looking for a full time job again.  Now she is my competition with a huge leg up on me since she has I have no idea how many years of teaching experience.  Either way, it was really nice to see her.  She looked exactly the same she did 18 years ago!  Time sure does fly!