Bro, that's why i am strictly against 1GB RAM Androids. This is very common in them and cannot be optimised sufficiently by manufacturers, as it has more link with user installed apps which are very RAM intensive.
RAM has direct link with multitasking, and we all multitask by opening multiple apps simultaneously and switching back and forth between them. In Android, many of the apps stay open in background (consuming RAM) even when you are not actively using them. So higher RAM is must.
More RAM can handle more apps running simultaneously. In 1GB RAM phone, you get ~400-500 mb free RAM for user installed apps, whereas in 2GB RAM, you get ~1.2GB for user installed apps. 2GB RAM offers upto 3 times more multitasking capabilities than 1GB RAM, which is why i always rant about spending a little more and getting atleast 1.5-2GB RAM phones.
As a general info for Androids,
1GB RAM phone can multitask between ~4 apps simultaneously.
2GB RAM phone can multitask between ~8-12 apps simultaneously.