How long did you ride time wise? How far did you go? Do the math and that is the average... Now if you feel that someone/something was either messing with time or space during this ride... then perhaps it was "meaningless."
On the other hand, if you want a true reading of how well you can maintain a pace over a specific distance... use an uninterrupted distance. (i.e. can you maintain 18MPH for 10miles... best to use an uninterrupped test track... like
Merckx's 30MPH. )
Frankly I use average time/speed simply as a metric against other rides on the same route. I average 16.1 one day, and 15.5 on another day... and nothing has changed, then I know, inspite of how I felt... I rode slower.
"Feeling" is an odd thing... one can feel fast but be riding slow... depending on health, how fast the background or others go by, or how one feels at the end of the ride... But the numbers don't lie.
I don't rely on average to tell me that I held 25MPH for a mile... only to tell me that what I did overall.