It has been stated that "It is better to give than receive".
For illustration purposes, lets use a scale of 1% to 100%.
Now when two or more people are involved, there is a scale for every person, so everything works out, but when the same person does the giving and receiving, only one scale is available.
Since giving is better than receiving, giving has to be 51% or more, while receiving must be 49% or less. It can't be 50-50 because then giving cannot be better than receiving.
It would be rediculous to give myself a gift that I don't like, especially since I know what I like, and I want me to be happy, therefore, my receiving would most certainly be above 49%.
Since I like myself, I want me to be happy, so the giving would definitely be above 50%.
This would result in a score that is higher than 100%, which is impossible, and would constitute a major paradox.
Since I don't want to be responsible for the cataclysmic destruction of the universe, I just don't give myself anything.
It's much safer that way.
No one ever thanks me, though.