I see lots of would be singers who cant hear themselves for some reason and are off key, or mumbly, or just terrible. Gives me nightmares that I might be as oblivious as them and no one will tell me. I started singing because my bands actual singer left, but I hadn't got comfortable yet so I asked the lead guitar guy if I sounded alright (I knew I didn't), and he said "Dont worry, the guitar drowns you out anyway".

These days I'm a lot better at keeping in key and I mostly worry about expression and dynamics. But it took a while.