I want to know why you think that love, beauty and joy are irrational. “Not fully understood” and “irrational” are not synonyms.
I would be interested in knowing what you mean by fully understood and how you are defining love, beauty or joy.
For example, are we talking about maternal love that reduces a person's objectivity in most situations or romantic love when you become intensely attached to someone unstable and selfish or I love eating certain foods even though they are not good for me and sabotage my goal to reduce my percentage of body fat?
And by joy, do you mean for example the joy of putting yourself and your family's life and health at serious risk in order to get the adrenaline rush of doing a dangerous or reckless activity?