How long are seeds good for?

Just curious, and this may have been asked before proboably...

How long are seeds still good/viable for?

I had 2 killer strains, and pulled a few seeds off about a year ago.
(Or say there was a seed in a killer bag you plucked and kept..)
Growing irregularly goes as it goes, and I was wondering how long a reasonably sealed, mildew proof, dark cool compartment would preserve seeds?

I'm thinking 2-3 years, but I may be wrong.



TIA

If you keep them in a cool, dry, dark place they'll be good for years. I've read about seeds lasting 10-15 years.