You will hear the MTFU argument quite a bit.
But…
All the SRAM Pro Tour teams will now regularly use a 32 tooth rear cassette on stages with steep hills.
if its good enough for Contador…
(Dave Millar used a 36 tooth XX rear cassette with XX rear mech in the Giro – this is because he uses those ovoid chainrings, which are 130mm OCD only but 42:36 is the same as 36:32)
having the low gears gives you the option of spinning and using a different muscle group and you will get tired later.
I have had this conclusively proven to me in races in France where young riders with a jey 34:29 (haha benders) have then comprehensively spanked me up mountains by time gaps that are measured in geological terms.
You didnt say if you had a compact chainset?