Like most guitar players I’ve met, I started playing (and had my first lessons) around middle school age. Walk into any local guitar shop that hosts instructors and lessons and you’ll see plenty of 10-15 year olds walking into and out of their classes and learning Blues playing. In fact, most electric guitar players learned Blues and Pentatonic scales and Dominant 7th chords before anything else. It makes sense, since so many Classic Rock, Metal, and even some Rock/Pop songs incorporate aspects of Blues improvisation and chord progressions. However, people grow up and advance in their proficiency and begin to study the specific niche genres and styles they prefer individually… and sadly the Blues often gets left behind.
The side effect of this practice is that even advanced players retain only a minimal knowledge (or bag of tricks) when playing the Blues. This seems to be in direct opposition of the fundamental position of Blues as a genre among contemporary musicians— Blues is a universal language, and a likely first step when jamming with new players.
If you want to spice up your playing and shake the rust off of your Blues licks, listen to some Allman Bros and supplement your Dominant 7th chords with some alternative Dom.9ths. In a traditional 12 Bar I IV V progression, use a Dom.9th as the IV chord— you might also try changing up your right hand (sorry lefties) technique by incorporating dynamic changes in percussive strumming, or by sliding into or out of the IV using whole steps. You can find a prime example of this in “Stormy Monday”.