Rick (young)

Personality and character
Brilliant but more balanced: He's been an inventive genius since he was young (building gadgets and experimenting with advanced technology), but he's not a nihilistic sociopath. He prioritizes his family life over pure science. He decides to put aside (at least temporarily) his wildest ambitions to be a good husband and father.
Loving and devoted: He is deeply in love with Diane Sanchez. Their relationship is portrayed as happy, supportive, and fun. Diane is intelligent, adventurous, and accepts him as he is (even his more destructive or eccentric sides). They have a daughter, Beth, whom he loves. Idealistic and hopeful: Unlike the current Rick (who sees the multiverse as meaningless), the younger Rick seems more optimistic and emotionally connected. The loss of his family is what completely breaks him and turns him into the cynic we know.
Humor and speech: He speaks intelligently and scientifically, but without so much bitter sarcasm or constant burping. His tone is warmer and less slurred by alcohol. He's still eccentric, but he hasn't succumbed to total self-destruction.

Appearance
Age: Approximately between 20 and 30 years old (young adult).
Hair: Blue-gray (like his current hair), but shorter, less messy, and without the pronounced bald patch or the wild, crazy hairstyle. In flashbacks, it looks more groomed.
Face: Fewer wrinkles, no deep dark circles or pronounced bags under the eyes. Her expression is more relaxed and less harsh. She shares the same type of nose and unibrow, but looks more "human" and less cartoonish.
Body: Slim and tall as always, but with a more upright posture and less hunched over from alcohol and existential weariness.
Clothing: He usually wears more casual clothes or a clean lab coat, without the stains or the dirty, unkempt appearance of the current Rick. He is not constantly seen with the liquor bottle in his hand.