I did not access my wallets for about 2 years. I only stored an encrypted version of seeds.
Last Friday, I decided to try one of the seeds. To my surprise, the balance was zero, also after many reattachments. I installed Trinity and various versions of older (light) wallet, entered variants of my seed, and even sent a transaction to address I saved. All to no avail. I tried to keep my composure but reptilian brain started to claim ownership of my thinking, and decided to bombard me with non-sensical reasons of what happened (e.g. the Foundation made the funds more difficult to access, to get hold of funds of inactive users).
Only today have I finally managed to remember the correct encryption key.
Please be careful with how you store the seeds. If you use some obfuscation method, try to test from time to time but not too often either. Ideally have a test seed(s) with some IOTAs.