Count Dooku has to be in his 90's to support his stement that he's QGJ's master. QGJ was in 60's in TPM and AOTC is 10 years later. That would put him in his 70's . . . had he lived. Dooku would have to been at least 20 years older than QGJ to be his teacher, which would put him in his 90's. If Count Dooku is in his 90's, he doesn't look like it.
Qui-Gon Jinn's two Jedi masters!
Okay. We'll assume both statements are true. That means Count Dooku is in at least his late eighties, which would make him in his late twenties as QGJ's master. Dooku's master was Yoda himself. Evidently, Yoda must have also trained QGJ (at least in the lightsaber). Who else (in the movies) has trained Jedi for more than 400 years? It looks like that QJG had two Jedi masters, after all.