Irrational excitement and emotional thinking is fine

Yes, it's very fine.

Just before I decide to sell I hope the average investor wanting to get a piece of the great gains everyone has already gotten will be so irrational that he is willing to OVERPAY for the shares he buys.

Those that come late to join the party always seem to make that mistake. Buy when there is blood in the street, sell when people are dancing in the street.