I am blessed/cursed with living on top of THE hill in town. So on my commute, I get it every single day.
In May, when I first started riding, I had to stop and walk. Then it got to stop and blow, then climb back on.
In June, I managed the beeg one. Then the beeger stretch to my house.
Now I own every hill in this hilly part of town - just riding them and riding them and riding them seems to have made the biggest diff, plus I simply am riding a lot.
I have a 'cross bike, so my front is 46/36. Before a century a couple of weeks ago with two nasty climbs (one short and nasty, one nasty then long), I put an 11/27 cassette on my bike. That made a huge difference, but funny thing is I almost never use the 27 now! It is nice to have when I want to really spin up a steep hill, but I have managed to get comfortable standing in the pedals when I climb. Used to, about 5 revs standing and I would blow up my legs. Now I can go quite a ways longer, but still no pro.
And, I'm 53, just started riding in April after a 24 year hiatus, and am still a Clyde. Having seen the diff in climbing after losing 25, I am really interested in what the next 30 will do for me on the hills. But if I can do it - get over those hills - so can you. Just ride more hills....