Data has longed for emotions all his life, and recently he got his wish, but originally, Data was unable to experience emotions. Lore took advantage of this in 2369, when he secretly bombarded Data with signals that triggered negative emotions in his positronic brain. He manipulated Data to help the Borg, a race of people that are half human (or some other race) and half machine. Data was forced to preform dangerous tests on Geordi, which almost killed him. Once Data realized what was happening to him, he disassembled Lore and was able to help Geordi recover. Lore had previously stolen an emotion chip which was originally intended for Data. Data took this opportunity to take back the chip, which he later had Geordi install for him.
Data began to experience dreams in 2369 because of an accidental plasma shock he received while preforming an experiment. He learned that the intensity of the shock had triggered a program to help him dream. This program was supposed to be activated when he reached a certain level of development, but the plasma shock triggered it prematurely.
Data constructed an android daughter in 2336. He used a new positronic matrix transfer technology to duplicate his own neural pathways onto another positronic brain. He named his daughter "Lal," which is Hindi for "beloved." She showed exceptional promise, but died after living for only two short weeks when she experienced a serious failure in her positronic brain.
Data even has me as his pet cat. Once he tried to train me not to jump up on his console while he was working, but he failed. I couldn't help it - his work was just too interesting not to look at. Data programmed over 80 different feline food supplements into the replicator just for me. Data even composed an "Ode to Spot." Here it is in its entirety:
Felus catus. Is your taxonomic nomenclature
An endothermic quadruped, carnivorous by nature?
Your visual, olfactory, and auditory senses
Contribute to your hunting skills and natural defenses.
I find myself intrigued by your sub-vocal oscillations
A singular development of cat communications
That obviates your basic hedonistic predilection
For a rhythmic stroking of your fur to demonstrate affection.
A tail is quite essential for your acrobatic talents.
You would not be so agile if you lacked its counterbalance.
And when not being utilized to aid in locomotion.
It often serves to illustrate the state of your emotions.
Oh, Spot, the complex levels of behavior you display
Connote a fairly well developed cognitive array
And though you are not sentient, Spot, and do not comprehend,
I nonetheless consider you a true and valued friend.
Data also paints in his spare time, often using images from his dream program as inspiration. Along with his paintings, some of Data's most prized possessions are a hologram of Tasha Yar; a book containing a collection of Shakespeare's plays, which was given to Data by the captain; and his medals, which consist of a medal for valor and gallantry, a medal of honor with clusters, the legion of honor, and the star cross. Data also has a deck of cards which he uses when he plays poker with the crew.