Being average or excellent is relative. The people you find excellent may be average for a few others. Likewise, you thinking of yourself as being average does not rule out that you may be awesome for few people.
The key is — how do you conclude that you are average? By your own standards or by how others see you?
If we find ourselves as average by our own standards, it is time to evolve, optimize and channelize the energies and resources for the next benchmark. If others find us average, take it as a feedback (positively if it is constructive and disregard if it is not) but no need to lose sleep over it.