It was never you

Polar Camel Tumbler (bulleted items found on their website).

• Polar Camel 20 oz Cups Stainless Steel Travel Tumbler Mug features double-wall vacuum insulation with a clear lid.
• The mug has a narrower bottom to fit most standard cup holders.
• You would hardly be able to tell the difference between this Polar Camel cup and other popular Tumbler cups.
• It is 2X heat & cold resistant compared to a normal travel mug and is BPA and lead-free.
• Not recommended for dishwashers, hand wash only.
• 20 oz Polar Camel Metal Tumbler - Polar Camel (polarcamels.us)