Bertrand feels he can successfully succeed Ashley Cole as their first-choice left-back.
He told the London Evening Standard: "One of my virtues as an individual and as a player is patience. There were occasions where I wondered if it was going to happen for me at Chelsea but you have to think of things realistically. Obviously you have an ambition but I want to play for Chelsea and I never wanted to let that go. Thankfully I kept at it and I'm getting a few games now.
"There were times when I would be frustrated that I was going out on loan again but anyone would be like that in that situation.
"Thankfully, I've had my mother with me all the way and we have remained realistic. When we speak to each other we're not confused, we're realistic about our chances.
"I have been on the right process and the club showed their faith in me to hand out another [four-year] contract at the start of the season. It really gave me belief and confidence.
"I'm quite grounded as a person too so when things have and do get tough, I just have to realise why and what I'm doing all this for."