Florescent>LED, my senior moment

I was converting my last 2 - 4 foot florescent shop light to LED tubes and stopped by Home Depot to pick up the LED tubes. The only direct wire, ballast replacements they had were Toggled (brand name) single ended powered. I prefer the dual ended powered but since I was there I bought what they had. They were sold as a 2 pack with 2 new wired tombstones. Since my existing tombstones were not cracked and non-shunted I decided to just rewire my existing tombstones. Got the first fixture rewired and installed a lamp. Hit the switch and it lit up fine. Installed second tube and it did not light. Swapped the 2 tubes to verify my wiring and again the "bad" tube did not light. Hum, bad tube, stuck it back in the box to return to HD.
Rewired the second fixture and installed both tubes. Hit switch and neither lit up. Removed tubes and got my meter out verified I had 120 at the wired tombstone end. Pulled out the directions that came with the packaging, always a last resort:sad: Verified I had wired correctly. Read a note that said "Be sure to install the powered end of the tube to the rewired lampholder." DOH! Went back and reinstalled the lamps with the end marked 120VAC into the rewired tombstone, Guess what, all the bad lamps now worked.