Psp question, lost saved games in an update, can i get them back?

i got this psp alooong time ago and it came with some free games on it already, saved games on the memory stick. i lost the psp and found it more than 2 years on and it worked perfectly fine, but i realised i should probable update it since there was probably a much new and better update for it. I updated it to 6.38 and now all the games have gone, along with a rambo movie. can i get the games back?? thanks for your time