Originally Posted by
Retro Grouch
I like having overlapping gear combinations because it gives you options when to shift front chainrings. I tell new riders to think of your triple crankset as having 3 gear ranges: once for uphills, one for flat roads and one for downhills.
This. Exactly this. What he said.
You'll soon learn when to best shift the front derailleur. Three basic idea is to use the rear derailleur a lot and the front much less often.
And I'll also point out many seasoned cyclists take a while to get this.