My USB stick needs lubrication to penetrate the USB socket.?

I noticed this a few nights ago, when some commotion ensued upon my attempt to mount the device. I tried again and again to gently insert it, to tease it in, however, I could only do so by wiggling it to-and-fro. The host in which I was attempting to mount the stick presented a message advising me to lubricate the shaft, which I duly did. Several hours of satisfactory operation followed, but I am concerned at the sudden need to perform this extra step. Could anyone offer any advice to restore normal functionality?