What do the terms in bold mean in this song?

[quote]I should’ve been a cowboy. I should’ve learned to roll around. Wearing my [b]six shooter[/b], riding my pony across the cattle drive. Stealing a young girl’s heat, just like [b]Gene[/b] and [b]Roy[/b]. Singing those campfire songs….oooh, I should’ve been a cowboy…..[/quote]