still an immature kid

my previous boss told me that i'm an ungrateful and immature kid when i tendered. why? because i resigned 4 months after i was promoted. hence... ungrateful.

my current boss told me that i'm a selfish and immature kid when i tendered 2 days ago. and he's very dissapointed in me. why? because i'm leaving to go back to the big boys with big advertising dollar.

notice the similiarity? both bosses told me that i'm immature. why? i really do not know. am i immature for planning out my career path? am i immature to grow and expand my advertising portfolio? am i immature for accepting another agency's offer?

i cannot help what other think about me... but my stance remains. it's nothing personal, it's just business.