Through the years Johnny Galecki attends an event, United States, circa 1990s. (Photo by Vinnie Zuffante/Getty Images) (Vinnie Zuffante/Getty Images)
Through the years UNITED STATES - SEPTEMBER 28: ROSEANNE - "Party Politics" - Season Six - 9/28/93, Johnny Galecki (David), Sara Gilbert (Darlene) on the Disney General Entertainment Content via Getty Images Television Network comedy "Roseanne". Jackie and Roseanne plan a house-warming party for Jackie's new home., (Photo by ABC Photo Archives/Disney General Entertainment Content via Getty Images) (ABC Photo Archives/Disney General Entertainment Con)
Through the years LOS ANGELES - FEBRUARY 15 2007: Johnny Galecki stars in THE BIG BANG THEORY on the CBS Television Network. (Robert Voets/CBS via Getty Images) (CBS Photo Archive/CBS via Getty Images)
Through the years BEVERLY HILLS, CA - JANUARY 10: Actors Johnny Galecki (L) and Kaley Cuoco pose with the J&A Footwear Athena Alexander / Callisto of California / Lia Bijou display during the HBO Luxury Lounge in honor of the 66th Annual Golden Globes held at the Four Seasons Hotel on January 10, 2009 in Beverly Hills, California. (Photo by Ray Mickshaw/Getty Images for mediaplacement) (Ray Mickshaw)
Through the years SAN DIEGO - JULY 24: Actors Johnny Galecki and Zachary Levi attend TV Guide Comic-con Panel during Comic-Con 2009 held at San Diego Convention Center on July 24, 2009 in San Diego, California. (Photo by John Shearer/Getty Images) (John Shearer/Getty Images)
Through the years SAN DIEGO - JULY 23: (L-R) Actors Kaley Cuoco, Simon Helberg, Jim Parsons, Kunal Nayyar and Johnny Galecki attend TV.com NOW Awards during Comic-Con 2010 at PETCO Park on July 23, 2010 in San Diego, California. (Photo by Frazer Harrison/Getty Images for TV.com) (Frazer Harrison)
Through the years LOS ANGELES - SEPTEMBER 22 : The Big Bang Theory cast members Simon Helberg, Kunal Nayyar, Jim Parsons, and Johnny Galecki join host Craig Ferguson, center, on CBS' THE LATE LATE SHOW W/ CRAIG FERGUSON on Wednesday, Sept. 22 on the CBS Television Network. (Photo by Sonja Flemming/CBS via Getty Images) (CBS Photo Archive/CBS via Getty Images)
Through the years WASHINGTON, DC - APRIL 28: Actor John Galecki attends the Capitol File's 7th Annual White House Correspondents' Association Dinner after party at The Newseum on April 28, 2012 in Washington, DC. (Photo by Stephen Lovekin/Getty Images) (Stephen Lovekin/Getty Images)
Through the years SAN DIEGO, CA - JULY 19: In this handout photo provided by WBTV, THE BIG BANG THEORY stars Melissa Rauch and Johnny Galecki atop the Warner Bros. booth at Comic-Con held at the San Diego Convention Center on July 19, 2013 in San Diego, California. (Photos by Chris Frawley/WBTV via Getty Images) (Handout/Getty Images)
Through the years BEVERLY HILLS, CA - MARCH 09: (L-R) Actors Simon Helberg, Mayim Bialik and Johnny Galecki perform onstage during the 24th and final "A Night at Sardi's" to benefit the Alzheimer's Association at The Beverly Hilton Hotel on March 9, 2016 in Beverly Hills, California. (Photo by Jesse Grant/Getty Images) (Jesse Grant/Getty Images)
Through the years BEVERLY HILLS, CA - MARCH 09: (L-R) Actors Jim Parsons, Melissa Rauch, Kunal Nayyar, Kaley Cuoco, Simon Helberg, Mayim Bialik and Johnny Galecki perform onstage during the 24th and final "A Night at Sardi's" to benefit the Alzheimer's Association at The Beverly Hilton Hotel on March 9, 2016 in Beverly Hills, California. (Photo by Jesse Grant/Getty Images) (Jesse Grant/Getty Images)
Through the years HOLLYWOOD, CALIFORNIA - MARCH 16: Actors Johnny Galecki and Simon Helberg attend The Paley Center For Media's 33rd Annual PALEYFEST Los Angeles ÔThe Big Bang Theory' at Dolby Theatre on March 16, 2016 in Hollywood, California. (Photo by Matt Winkelmeyer/Getty Images) (Matt Winkelmeyer/Getty Images)
Through the years LAKE BUENA VISTA, FL - MAY 04: In this handout photo provided by Disney Resorts, actor Johnny Galecki and his niece, Luci, pose with Pluto at the Mission: Space attraction at Epcot at Walt Disney World on May 4, 2016 in Lake Buena Vista, Florida. (Photo by Courtney Di Stasio/Disney Resorts via Getty Images) (Handout/Getty Images)
Through the years NEW YORK, NY - JANUARY 20: Johnny Galecki visits Build Series to discuss the movie "Rings" at Build Studio on January 20, 2017 in New York City. (Photo by Jamie McCarthy/Getty Images) (Jamie McCarthy/Getty Images)
Through the years HOLLYWOOD, CALIFORNIA - MAY 01: (L-R) Johnny Galecki, Jim Parsons, Kaley Cuoco, Simon Helberg, Kunal Nayyar, Mayim Bialik and Melissa Rauch from the cast of "The Big Bang Theory" attend their handprint ceremony at the TCL Chinese Theatre IMAX on May 1, 2019 in Hollywood, California. (Photo by Rich Fury/Getty Images) (Rich Fury/Getty Images)
Through the years HOLLYWOOD, CALIFORNIA - MAY 01: Johnny Galecki, Jim Parsons and Kaley Cuoco from the cast of "The Big Bang Theory" pose during their handprint ceremony at the TCL Chinese Theatre IMAX on May 01, 2019 in Hollywood, California. (Photo by Rich Fury/Getty Images) (Rich Fury/Getty Images)
Through the years BEVERLY HILLS, CALIFORNIA - DECEMBER 12: (L-R) Johnny Galecki, Juliette Lewis, Diane Ladd, Chevy Chase and Beverly D'Angelo attend the Academy of Motion Picture Arts and Sciences 30th Anniversary Screening of "National Lampoons Christmas Vacation" at the AMPAS Samuel Goldwyn theatre on December 12, 2019 in Beverly Hills, California. (Photo by Jean Baptiste Lacroix/Getty Images) (Jean Baptiste Lacroix/Getty Images)
Through the years WEST HOLLYWOOD, CALIFORNIA - FEBRUARY 08: Johnny Galecki (L) performs with Robby Krieger of The Doors (R) at the Sunset Marquis on February 08, 2020 in West Hollywood, California. (Photo by Erik Voake/Getty Images) (Erik Voake/Getty Images)
