Disappointment is…
!) The feeling of sadness or displeasure caused by the nonfulfillment of one’s hopes or expectations;
2) The person, event, or thing that causes such a feeling.
Love is…
1) An intense feeling of deep affection; a sexual or romantic attachment; a great interest and pleasure or fondness in a subject;
2) The person or thing that one loves; slang for addressing another; formality when signing off mail;
3) A score of zero (usually in squash or tennis) [ORIGIN: apparently from the phrase play for love (i.e., the love of the game, not for money); folk etymology has connected the word with French l'oeuf ‘egg,’ from the resemblance in shape between an egg and a zero.]
So how not to get disappointed? Don’t have expectations or hopes!
Or just don’t love;
You care: you worry.
You’re fond: you’re jealous.
You’re responsible: you’re troubled.
You’re enjoying the moment: You’re getting sick of it.
You promise: You disappoint.
“Don’t love” too extreme?
Don’t give your love easily.
Easily said, but impossible it’s not.