Wanting stronger tea

I have been a tea drinker since I was a child. Over the past few years (now age 30) I have noticed that tea doesn't taste strong or fragrant enough, particularly tea bags. I have switched to stronger teas twice now and have found that after a few months it begins to have that bland flavour. I'm currently on Yorkshire "proper strong" black tea.

I feel like my taste buds have built up a tolerance.

I've tried buying a tea cannister as I find the fresher the tea the better it tastes, which seemed to work a bit. My brother said for stronger tea you need more tea leaves. Maybe I will have to use two bags!

Has anyone else experienced this phenomenon?